kimun_notes/app_screen/

editor.rs

use std::sync::Arc;
use std::time::Duration;

use async_trait::async_trait;
use kimun_core::NoteVault;
use kimun_core::error::{FSError, VaultError};
use kimun_core::nfs::VaultPath;
use ratatui::layout::{Constraint, Direction, Layout};
use ratatui::style::Style;
use ratatui::widgets::Paragraph;

use crate::app_screen::ask::AskCoordinator;
use crate::app_screen::editor_input::{
    Classification, CycleDir, EditorIntent, EditorOp, InputCtx, OverlayOpen, PanelFallback,
    classify,
};
use crate::app_screen::overlay_host::OverlayHost;
use crate::app_screen::panel_set::PanelSet;
use crate::app_screen::{AppScreen, ScreenKind};
use crate::components::ask_thread::ThreadPanel;
use crate::components::attachment_view::AttachmentView;
use crate::components::autosave_timer::AutosaveTimer;
use crate::components::dialogs::ActiveDialog;
use crate::components::drawer::{DrawerHost, DrawerView};
use crate::components::drawer_views::{LinksPanel, OutlinePanel, TagsPanel};
use crate::components::event_state::EventState;
use crate::components::events::{
    AppEvent, AppTx, FileOp, InputEvent, OverlayData, SaveSource, SavedSearchFlow, ScreenEvent,
    SortTarget, UpdateFlow,
};
use crate::components::file_list::FileListEntry;
use crate::components::footer_bar::FooterBar;
use crate::components::note_browser::file_finder_provider::FileFinderProvider;
use crate::components::note_browser::search_provider::resolving_search_source;
use crate::components::note_browser::{BrowserScope, NoteBrowserModal};
use crate::components::overlay::{Overlay, OverlayKind};
use crate::components::panel::PanelKind;
use crate::components::query_panel::QueryPanel;
use crate::components::saved_searches_modal::SavedSearchesModal;
use crate::components::sidebar::SidebarComponent;
use crate::components::text_editor::TextEditorComponent;
use crate::keys::KeyBindings;
use crate::keys::action_shortcuts::ActionShortcuts;
use crate::keys::leader::{LeaderAction, LeaderEngine, LeaderOutcome};
use crate::settings::SharedSettings;
use crate::settings::icons::Icons;
use crate::settings::themes::Theme;
use crate::util::single_slot_task::SingleSlotTask;

/// Hard cap on every blocking save path so a stuck disk (NFS hang,
/// fsync stall) cannot freeze quit, navigation, or the next autosave
/// tick. The same value is used both to wait for an in-flight
/// background autosave and to bound our own synchronous save call —
/// the worst-case quit time is therefore one cap plus the
/// observability of `abort()` on a syscall in progress.
const SAVE_TIMEOUT: Duration = Duration::from_secs(5);

pub struct EditorScreen {
    vault: Arc<NoteVault>,
    settings: SharedSettings,
    icons: Icons,
    theme: Theme,
    /// The persistent panels (sidebar, editor, Query panel) plus their order,
    /// visibility, and focus. The host reaches a specific panel through the
    /// typed accessors (`panels.editor_mut()`, …) for panel-specific calls.
    panels: PanelSet,
    path: VaultPath,
    footer: FooterBar,
    /// Async document/status state: backlink count, git summary, link
    /// affordance cache, pending emphasis needles (see `doc_meta.rs`).
    doc_meta: crate::app_screen::doc_meta::DocMeta,
    /// App-global update notice, seeded by `AppEvent::Update(UpdateFlow::Available)`. Drives
    /// the footer indicator; `None` when up to date or the check found nothing.
    update: Option<crate::update::UpdateStatus>,
    /// Latest RAG connection/sync status from the background sync task, shown in
    /// the footer. `Disabled` (no server) renders nothing.
    rag_status: crate::rag::RagStatus,
    /// The Ask workspace's coordination layer: Thread↔Sources sync, capability
    /// refresh, AskData routing, and show/stash transitions (see `ask.rs`).
    ask: AskCoordinator,
    /// The leader-key sequence state machine (Ctrl-G gateway, spec §8a).
    leader: LeaderEngine,
    /// The mouse presses currently forming one gesture, so a double-click in
    /// the editor can follow a link (see `click_run`). Fed before each
    /// classification; its answer reaches the classifier as `InputCtx`.
    clicks: crate::app_screen::click_run::ClickRun,
    /// App event sender, captured on enter — render-side async kicks (the
    /// link-affordance backlink fetch) need it where no `tx` is threaded.
    app_tx: Option<AppTx>,
    autosave: AutosaveTimer,
    /// The active overlay, if any. An open overlay intercepts input ahead of
    /// the panels; closing it restores focus to the panel that opened it.
    overlays: OverlayHost<PanelKind>,
    /// Handle to the most recently spawned background autosave task.
    /// `is_in_flight()` is the source of truth for "is a save still in
    /// flight"; both successful completion AND panic flip it to false
    /// so the next periodic tick can spawn fresh. The synchronous save
    /// paths (`open_path` / `on_entry_op` / `on_exit`) await this slot
    /// before issuing their own `vault.save_note`, so two concurrent
    /// writes for the same path can never collide. Drop aborts the
    /// in-flight task so the spawned future cannot outlive the screen.
    autosave_task: SingleSlotTask<()>,
}

impl EditorScreen {
    pub fn new(vault: Arc<NoteVault>, path: VaultPath, settings: SharedSettings) -> Self {
        let s = settings.read().unwrap();
        let kb = s.key_bindings.clone();
        let theme = s.get_theme();
        let footer = FooterBar::new();
        let icons = s.icons();
        let sidebar = SidebarComponent::from_settings(vault.clone(), &s);
        let query_panel = QueryPanel::new(vault.clone(), kb.clone(), icons.clone());
        let semantic = crate::components::semantic_search::SemanticPanel::new(
            vault.clone(),
            settings.clone(),
            s.icons(),
            s.yank_combos(),
        );
        let tags = TagsPanel::new(vault.clone(), s.icons(), s.yank_combos());
        let links = LinksPanel::new(vault.clone(), s.icons(), s.yank_combos());
        let outline = OutlinePanel::new(vault.clone(), s.icons(), s.yank_combos());
        let drawer = DrawerHost::new(
            vault.clone(),
            &kb,
            sidebar,
            query_panel,
            semantic,
            tags,
            links,
            outline,
        );
        let rail_kb = kb.clone();
        let mut editor = TextEditorComponent::new(kb, &s);
        editor.set_vault(vault.clone());
        let leader_engine = LeaderEngine::with_tree(s.leader_tree());
        drop(s);
        let rail_icons = icons.clone();
        let ask = AskCoordinator::new(settings.clone(), vault.clone());
        Self {
            settings,
            icons,
            theme,
            // SEM and ASK both start hidden: no RAG status has arrived yet, so
            // the server's search/LLM capability is unknown. The rail rebuilds
            // when the first health probe lands (both are status-driven).
            panels: PanelSet::from_panels(
                drawer,
                editor,
                rail_icons,
                rail_kb,
                crate::components::activity_rail::RailCaps {
                    semantic: false,
                    ask: false,
                },
            ),
            doc_meta: crate::app_screen::doc_meta::DocMeta::new(vault.clone()),
            update: None,
            rag_status: crate::rag::RagStatus::Disabled,
            ask,
            vault,
            path,
            footer,
            leader: leader_engine,
            clicks: Default::default(),
            app_tx: None,
            autosave: AutosaveTimer::new(),
            overlays: OverlayHost::new(),
            autosave_task: SingleSlotTask::empty(),
        }
    }
}

/// Encodes raw RGBA pixels as a PNG byte stream.
fn encode_rgba_to_png(width: u32, height: u32, rgba: &[u8]) -> std::io::Result<Vec<u8>> {
    let mut buf = Vec::new();
    {
        let mut encoder = png::Encoder::new(&mut buf, width, height);
        encoder.set_color(png::ColorType::Rgba);
        encoder.set_depth(png::BitDepth::Eight);
        let mut writer = encoder
            .write_header()
            .map_err(|e| std::io::Error::new(std::io::ErrorKind::InvalidData, e))?;
        writer
            .write_image_data(rgba)
            .map_err(|e| std::io::Error::new(std::io::ErrorKind::InvalidData, e))?;
    }
    Ok(buf)
}

impl EditorScreen {
    /// Pulls an image off the system clipboard, encodes it to PNG, saves it as
    /// an attachment under the vault's `/assets` directory, and inserts a
    /// markdown image link (relative to the current note) at the cursor.
    ///
    /// Returns `true` if a clipboard image was found and the paste was
    /// dispatched — even if the encode/save is still in flight. Returns
    /// `false` if the clipboard contained no image, so the caller can fall
    /// through to a regular text paste.
    fn try_paste_image(&mut self, tx: &AppTx) -> bool {
        let Some(editor) = self.panels.editor_mut() else {
            return false;
        };
        let img = match editor.take_clipboard_image() {
            Some(i) if !i.rgba.is_empty() && i.width > 0 && i.height > 0 => i,
            _ => return false,
        };
        // arboard contract: rgba length == width * height * 4. A mismatch means
        // a misbehaving clipboard provider — refuse rather than encode garbage.
        let expected = img
            .width
            .checked_mul(img.height)
            .and_then(|n| n.checked_mul(4));
        if expected != Some(img.rgba.len()) {
            self.footer
                .flash("Clipboard image size mismatch".to_string(), tx);
            return true;
        }
        // The selection is NOT dropped here. Both steps below can fail — the
        // PNG encode and the attachment save — and a cut done now would destroy
        // the user's text with nothing to replace it. `insert_at_cursor`, which
        // runs only on success, does the replacement and reconciles the vim
        // engine out of Visual in the same breath.
        let asset_path = self.vault.generate_attachment_path("image", "png");
        let link_path = asset_path.relative_link_from_note(&self.path);
        let markdown = format!("![]({link_path})");
        let vault = self.vault.clone();
        let tx2 = tx.clone();
        let width = img.width as u32;
        let height = img.height as u32;
        let rgba = img.rgba;
        tokio::spawn(async move {
            // PNG encoding is CPU-bound — keep it off the runtime worker threads.
            let png_bytes =
                match tokio::task::spawn_blocking(move || encode_rgba_to_png(width, height, &rgba))
                    .await
                {
                    Ok(Ok(b)) => b,
                    Ok(Err(e)) => {
                        tx2.send(AppEvent::OverlayData(OverlayData::Error(format!(
                            "Image encode failed: {e}"
                        ))))
                        .ok();
                        return;
                    }
                    Err(e) => {
                        tx2.send(AppEvent::OverlayData(OverlayData::Error(format!(
                            "Image encode task failed: {e}"
                        ))))
                        .ok();
                        return;
                    }
                };
            match vault.save_attachment(&asset_path, &png_bytes).await {
                Ok(()) => {
                    tx2.send(AppEvent::InsertAtCursor(markdown)).ok();
                    // Only on success — the failure branches below already
                    // report, and this path is async, so the chord echo would
                    // otherwise be the last thing the user saw.
                    tx2.send(AppEvent::FlashMessage("image pasted".into())).ok();
                }
                Err(e) => {
                    tx2.send(AppEvent::OverlayData(OverlayData::Error(format!(
                        "Image save failed: {e}"
                    ))))
                    .ok();
                }
            }
        });
        true
    }

    /// Persist a saved search via core. Used by the SaveSearchConfirmed handler
    /// and unit tests.
    #[cfg(test)]
    async fn persist_saved_search(&self, name: &str, query: &str) -> Result<(), VaultError> {
        self.vault.save_search(name, query).await
    }

    async fn follow_link(&mut self, target: String, tx: &AppTx) {
        // External URL — hand off to the OS browser/handler.
        if kimun_core::note::scan::is_remote_url(&target) {
            match open::that_detached(&target) {
                Ok(()) => self.footer.flash(format!("Opening {target}"), tx),
                Err(e) => self.footer.flash(format!("Cannot open URL: {e}"), tx),
            }
            return;
        }

        // Image attachment — resolve the (potentially relative) path against
        // the current note's directory, convert to an OS path, hand off to the
        // OS default handler. Images are not notes, so skip the note lookup.
        if kimun_core::note::scan::target_looks_like_image(&target) {
            let parent = self.path.get_parent_path().0;
            let resolved = parent.append(&VaultPath::new(target.trim()));
            let os_path = self.vault.path_to_pathbuf(&resolved);
            match open::that_detached(&os_path) {
                Ok(()) => self.footer.flash(format!("Opening {target}"), tx),
                Err(e) => self.footer.flash(format!("Cannot open image: {e}"), tx),
            }
            return;
        }

        // Note reference — look it up in the vault.
        // Strip any `#fragment` suffix before resolving (e.g. `notes/design.md#goals`
        // should resolve to `notes/design.md`, not `notes/design.md#goals.md`).
        let target_clean = target.split('#').next().unwrap_or(&target).trim_end();
        // Resolve the (possibly relative, e.g. `../work/anton.md`) target
        // against this note's directory so the existence lookup uses the same
        // absolute path the note is stored under. Bare names stay name-lookups.
        let path = kimun_core::nfs::VaultPath::note_path_from(target_clean)
            .resolve_link_in_note(&self.path);
        match self.vault.open_or_search(&path).await {
            Ok(results) if results.is_empty() => {
                self.present_overlay(Box::new(ActiveDialog::create_note(
                    path,
                    self.vault.clone(),
                    None,
                )));
            }
            Ok(mut results) if results.len() == 1 => {
                let (entry, _) = results.remove(0);
                self.open_path(entry.path, None, tx).await;
            }
            Ok(results) => {
                use crate::components::note_browser::link_results_provider::LinkResultsProvider;
                let provider = LinkResultsProvider::from_results(results);
                let s = self.settings.read().unwrap();
                let modal = NoteBrowserModal::new(
                    format!("Follow: {target}"),
                    BrowserScope::Files,
                    provider,
                    self.vault.clone(),
                    s.key_bindings.clone(),
                    s.icons(),
                    tx.clone(),
                );
                drop(s);
                self.present_overlay(Box::new(modal));
            }
            Err(e) => {
                self.footer.flash(format!("Link error: {e}"), tx);
            }
        }
    }

    pub async fn open_path(&mut self, path: VaultPath, emphasis: Option<Vec<String>>, tx: &AppTx) {
        if !path.is_note() {
            // A non-note path is either an attachment (show it in place of the
            // editor) or a directory (browse it). Classify so a stray
            // attachment open here still lands in the attachment view rather
            // than the directory browser.
            if let Ok(kimun_core::EntryKind::Attachment) = self.vault.entry_kind(&path).await {
                self.open_attachment(path, tx).await;
                return;
            }
            tx.send(AppEvent::OpenScreen(ScreenEvent::OpenBrowse(
                self.vault.clone(),
                path,
            )))
            .ok();
            return;
        }

        // Save current note before switching
        self.try_save().await;

        {
            let mut s = self.settings.write().unwrap();
            s.add_path_history(&path);
        }
        let settings_snapshot = self.settings.read().unwrap().clone();
        tokio::spawn(async move {
            settings_snapshot.save_to_disk().ok();
        });

        self.path = path.clone();
        // Returning to a note swaps the editor area back from any attachment or
        // the Ask workspace. `clear_attachment` and `hide_ask_if_shown` each
        // only touch their own content, so both are needed to guarantee the
        // note editor is what shows (carry-forward: open note over Ask/attach).
        self.hide_ask_if_shown();
        self.panels.clear_attachment();
        // Mark this note's row in the sidebar (clears the previous one).
        self.panels
            .sidebar_mut()
            .set_open_note(Some(self.path.clone()));
        match self.vault.get_note_text(&self.path).await {
            Ok(content) => {
                self.doc_meta.note_opened(&self.path, tx);
                if let Some(ed) = self.panels.editor_mut() {
                    ed.set_text(content);
                    // Arrive-from-query emphasis: apply after the load so the
                    // buffer's new revision owns the needles.
                    if let Some(needles) = emphasis {
                        ed.set_search_needles(needles);
                    }
                    ed.set_redraw_tx(tx);
                }
                tx.send(AppEvent::Redraw).ok();
                // FIND / LINKS / OUTLINE reflect the open note; keep them in
                // step. Shared with `on_note_renamed` via the helper.
                self.reflect_open_note_in_drawers(tx);
            }
            Err(e) => {
                if matches!(e, VaultError::FSError(FSError::VaultPathNotFound { .. })) {
                    self.present_overlay(Box::new(ActiveDialog::create_note(
                        self.path.clone(),
                        self.vault.clone(),
                        None,
                    )));
                } else {
                    tracing::error!("Failed to read note {}: {e}", self.path);
                    let parent = self.path.get_parent_path().0;
                    tx.send(AppEvent::OpenScreen(ScreenEvent::OpenBrowse(
                        self.vault.clone(),
                        parent,
                    )))
                    .ok();
                }
                return;
            }
        }

        // Load the sidebar on first open only; refreshes happen via explicit
        // create/rename/delete/move events, not on every note open.
        let note_parent = path.get_parent_path().0;
        if self.panels.sidebar().is_empty() {
            self.navigate_sidebar(note_parent, tx);
        }

        // Abort any existing timer and spawn a fresh one for the new note.
        let interval = self.settings.read().unwrap().autosave_interval_secs;
        self.autosave.restart(interval, tx.clone());
    }

    /// Take the editor area off the Ask workspace before it's swapped to
    /// another view (a note or an attachment). `clear_attachment` and
    /// `show_attachment` both leave Ask content alone, so this is what
    /// guarantees the new view actually shows (see
    /// `AskCoordinator::hide_if_shown` for the drawer-view rules).
    fn hide_ask_if_shown(&mut self) {
        self.ask.hide_if_shown(&mut self.panels);
    }

    /// Show the attachment at `path` in the editor area's read-only attachment
    /// view. Saves and unmounts the open note first; while an
    /// attachment is shown there is no open note, so the autosave task is
    /// aborted and the sidebar's open-note marker cleared. The next periodic
    /// autosave tick no-ops because the note editor is absent.
    async fn open_attachment(&mut self, path: VaultPath, tx: &AppTx) {
        // Persist the current note before swapping the editor area away from it.
        self.try_save().await;
        self.autosave_task.abort();

        match self.vault.get_attachment_details(&path).await {
            Ok(details) => {
                let (icons, kb) = {
                    let s = self.settings.read().unwrap();
                    (s.icons(), s.key_bindings.clone())
                };
                let view = AttachmentView::new(details, icons, kb);
                self.path = path;
                // Take the area off Ask so the attachment actually replaces it
                // (show_attachment leaves Ask content alone).
                self.hide_ask_if_shown();
                self.panels.show_attachment(view);
                self.panels.sidebar_mut().set_open_note(None);
                tx.send(AppEvent::Redraw).ok();
            }
            Err(e) => {
                self.footer
                    .flash(format!("Cannot open attachment: {e}"), tx);
            }
        }
    }

    fn navigate_sidebar(&mut self, dir: VaultPath, tx: &AppTx) {
        // The sidebar hosts a streamed `SearchList`; (re)building its engine for
        // `dir` runs `browse_vault_stream` inside the source and emits rows as they
        // arrive (with a redraw on each).
        self.panels.sidebar_mut().navigate(dir, tx);
    }

    /// Rebuild the sidebar listing only when it is currently showing `dir` —
    /// used after entry create/rename/move ops so the change appears without
    /// yanking the user away from an unrelated directory they browsed to.
    /// Deliberately the inverse of `reveal_note_dir_in_sidebar`, which
    /// navigates when the sidebar is NOT on the target dir.
    fn refresh_sidebar_if_showing(&mut self, dir: &VaultPath, tx: &AppTx) {
        self.panels.sidebar_mut().refresh_if_showing(dir, tx);
    }

    /// A note at `path` was just saved with raw title `raw_title`; update its
    /// sidebar row in place. Keyed by the saved path, not the open note, so a
    /// just-saved-then-deselected note's row updates too.
    fn note_saved(&mut self, path: &VaultPath, raw_title: String) {
        let title = FileListEntry::display_title(raw_title);
        self.panels.sidebar_mut().update_note_row(path, &title);
    }

    async fn try_save(&mut self) {
        // Wait out any background autosave so two concurrent `vault.save_note`
        // calls cannot race on the same path. Capped at 5s so a wedged
        // filesystem (NFS hang, fsync stall, SQLite lock contention) does
        // not freeze app-quit indefinitely.
        //
        // If the timeout fires we MUST abort the prior task and bail
        // without issuing our own save: dropping a JoinHandle detaches
        // the tokio task rather than cancelling it, so the spawned
        // vault.save_note keeps running. Calling our own vault.save_note
        // on the same path on top of that is the exact two-writer race
        // the in-flight serialisation is meant to prevent. abort() is
        // best-effort (will not unwind an in-progress syscall) but it
        // stops any further await points in the spawned task. The editor
        // stays dirty so the next session retries; the spawned task
        // either finishes against the disk on its own or is killed when
        // the process exits.
        if self.autosave_task.is_in_flight() {
            match self.autosave_task.await_with_timeout(SAVE_TIMEOUT).await {
                Some(_) => {} // completed (success or panic) — slot already cleared
                None => {
                    // Timeout: abort the spawned task and bail.
                    self.autosave_task.abort();
                    return;
                }
            }
        }
        // No note editor mounted (an attachment is shown) → nothing to save.
        let Some(text) = self
            .panels
            .editor()
            .filter(|e| e.is_dirty())
            .map(|e| e.get_text())
        else {
            return;
        };
        // Same cap on our own save so quit cannot hang on a stuck
        // disk. A timeout returns Err(_); we skip mark_saved so the
        // editor stays dirty for any subsequent retry.
        let save = self.vault.save_note(&self.path, &text);
        if let Ok(Ok((_, content))) = tokio::time::timeout(SAVE_TIMEOUT, save).await {
            if let Some(ed) = self.panels.editor_mut() {
                ed.mark_saved(text);
            }
            let path = self.path.clone();
            self.note_saved(&path, content.title);
        }
    }

    /// Fire-and-forget autosave used by the periodic timer. The save runs in
    /// a spawned tokio task so the main event loop is never blocked by the
    /// filesystem + SQLite write. Completion is reported back as
    /// `AppEvent::AutosaveCompleted`, which marks the editor clean iff the
    /// editor is still at the revision that was written. `is_in_flight()`
    /// on the `SingleSlotTask` slot is the "is a save in flight" signal;
    /// it flips to false on both successful completion AND panic, so a
    /// single panicked task can never permanently disable autosave.
    fn spawn_autosave(&mut self, tx: &AppTx) {
        // A previous task that hasn't reported completion yet still holds the
        // lock on the file system + SQLite path; let it finish first.
        if self.autosave_task.is_in_flight() {
            return;
        }
        let Some(ed) = self.panels.editor() else {
            return;
        };
        if !ed.is_dirty() {
            return;
        }
        let text = ed.get_text();
        let revision = ed.content_revision();
        let vault = self.vault.clone();
        let path = self.path.clone();
        let tx = tx.clone();
        self.autosave_task.spawn(async move {
            let (saved_revision, title) = match vault.save_note(&path, &text).await {
                Ok((_, content)) => (Some(revision), Some(content.title)),
                Err(_) => (None, None),
            };
            let _ = tx.send(AppEvent::AutosaveCompleted {
                path,
                saved_revision,
                title,
            });
        });
    }

    /// The panel to restore focus to when the active overlay closes — the
    /// panel that was focused when the overlay opened.
    fn opener_focus(&self) -> PanelKind {
        self.panels.focused()
    }

    /// Present `overlay`, recording the currently focused panel as its opener so
    /// `dismiss_overlay` can return there on close. The single way the editor
    /// opens an overlay — the focus contract lives here, not at each call site.
    fn present_overlay(&mut self, overlay: Box<dyn Overlay>) {
        // An overlay taking input must never leave a leader sequence armed —
        // its keys would be eaten by the leader intercept.
        self.leader.cancel();
        let opener = self.opener_focus();
        self.overlays.open(overlay, opener);
    }

    /// Close the active overlay and restore focus to the panel that opened it.
    /// The close-side mirror of `present_overlay`. `OverlayHost::close` returns
    /// `None` when nothing is open, so this is a no-op then — which is also why
    /// a selection that closed the overlay itself (and chose its own focus) is
    /// not re-restored by a trailing `CloseOverlay`.
    fn dismiss_overlay(&mut self) {
        if let Some(opener) = self.overlays.close() {
            self.panels.focus(opener);
        }
    }

    async fn on_entry_op(&mut self, from: VaultPath, tx: &AppTx) {
        self.dismiss_overlay();
        // `is_like` ignores the vault-relative/absolute distinction: `from` (from
        // a sidebar/query row) is index-absolute while `self.path` may be relative.
        // A plain `==` would miss, leaving the stale autosave to
        // recreate a deleted/moved note.
        if from.is_like(&self.path) {
            self.autosave.stop();
            self.try_save().await;
            let parent = self.path.get_parent_path().0;
            tx.send(AppEvent::OpenScreen(ScreenEvent::OpenBrowse(
                self.vault.clone(),
                parent,
            )))
            .ok();
        } else {
            self.refresh_sidebar_if_showing(&from.get_parent_path().0, tx);
        }
    }

    /// A note was renamed. Update its sidebar row in place; if it is the note
    /// currently open, retarget the editor to the new path and reload the body
    /// from disk so any self-link rewrites from the rename land in the buffer
    /// (the in-memory text still holds the pre-rename self-links). We
    /// deliberately do NOT `try_save` — the old path no longer exists on disk.
    async fn on_note_renamed(&mut self, from: VaultPath, to: VaultPath, tx: &AppTx) {
        self.dismiss_overlay();
        self.panels.sidebar_mut().rename_note_row(&from, &to);
        // `is_like` so an absolute `from` (index row) matches a possibly-relative
        // `self.path` — otherwise the retarget + autosave-abort below
        // are skipped and the stale save resurrects the old path.
        if from.is_like(&self.path) {
            // The open note was renamed. Kill any in-flight autosave still
            // targeting the OLD path before retargeting (spawn_autosave bakes
            // the path in; vault.save_note writes unconditionally, so a stale
            // save would recreate the renamed-away file). abort() is
            // best-effort (can't unwind a syscall already in progress).
            self.autosave_task.abort();
            match self.vault.get_note_text(&to).await {
                Ok(text) => {
                    self.path = to.clone();
                    if let Some(ed) = self.panels.editor_mut() {
                        ed.set_text(text.clone());
                        ed.mark_saved(text);
                    }
                    self.panels
                        .sidebar_mut()
                        .set_open_note(Some(self.path.clone()));
                    self.doc_meta.note_opened(&self.path, tx);
                    self.reflect_open_note_in_drawers(tx);
                    // Fresh autosave timer for the new path (mirrors open_path).
                    let interval = self.settings.read().unwrap().autosave_interval_secs;
                    self.autosave.restart(interval, tx.clone());
                }
                Err(_) => {
                    // Couldn't load the renamed note — do NOT keep a dirty
                    // buffer pointed at it (autosave would clobber the
                    // on-disk rewrite). Fall back to Browse on the new
                    // parent dir.
                    self.autosave.stop();
                    let parent = to.get_parent_path().0;
                    tx.send(AppEvent::OpenScreen(ScreenEvent::OpenBrowse(
                        self.vault.clone(),
                        parent,
                    )))
                    .ok();
                }
            }
        }
    }
}

impl EditorScreen {
    /// Snapshot of the screen state the input classifier reads. Built per
    /// classification — cheap field reads only.
    ///
    /// `double_click` comes from [`Self::track_click`] rather than a field read
    /// because feeding the click run mutates it; a snapshot is taken from
    /// `&self` and cannot.
    fn input_ctx(&self, double_click: bool) -> InputCtx {
        InputCtx {
            overlay: self.overlays.active_kind(),
            leader_pending: self.leader.is_pending(),
            focused: self.panels.focused(),
            drawer_view: self.panels.active_drawer_view(),
            space_leads: self.panels.editor().is_some_and(|e| e.space_leads()),
            claim: self.panels.editor().map(|e| e.claim()).unwrap_or_default(),
            double_click,
        }
    }

    /// Feed an event to the click run and report whether it completes a
    /// double-click on the note buffer.
    ///
    /// The screen answers only what a `ClickRun` cannot answer for itself:
    /// whether the event is a mouse event at all, whether an overlay is in the
    /// way, and whether the press landed on the note buffer. Which *mouse*
    /// events end a run is `ClickRun`'s policy and lives there, where it can be
    /// tested against a real event sequence.
    ///
    /// An open overlay ends the run rather than merely failing to extend it.
    /// The classifier already gives an overlay precedence, so no follow can
    /// fire *while* one is open — but a modal is drawn over the editor column,
    /// and a `SearchList` activates a row on a click-click of its own. Without
    /// ending it here, those presses stay in the run and pair with the first
    /// press that lands after the overlay closes.
    ///
    /// `now` is passed in for the same reason [`ClickRun`] takes it rather than
    /// reading a clock: a test describes a gap instead of sleeping through one.
    /// The seam matters more here than there — this half of the rule is the part
    /// that hit-tests, and the frame around the editor was counted as buffer
    /// until it could be asserted against.
    ///
    /// [`ClickRun`]: crate::app_screen::click_run::ClickRun
    fn track_click(&mut self, event: &InputEvent, now: std::time::Instant) -> bool {
        let InputEvent::Mouse(mouse) = event else {
            self.clicks.end();
            return false;
        };
        if self.overlays.is_open() {
            self.clicks.end();
            return false;
        }
        // Only a press consults the hit-test; `observe` discards the flag for
        // every other kind. Motion is the reason to care — any-event tracking
        // delivers one per cell of travel, and this would otherwise scan the
        // column rects twice for each.
        let on_buffer = matches!(
            mouse.kind,
            ratatui::crossterm::event::MouseEventKind::Down(_)
        ) && self.panels.is_note_buffer_cell(mouse.column, mouse.row);
        self.clicks.observe(mouse, on_buffer, now)
    }

    /// Apply a classification: pre-effects first (footer chord flash, leader
    /// cancel), then the intent. The classifier decides *what* an event
    /// means; everything that mutates happens here.
    fn apply_classification(
        &mut self,
        classification: Classification,
        event: &InputEvent,
        tx: &AppTx,
    ) -> EventState {
        if let Some(chord) = classification.flash {
            self.footer.flash(chord, tx);
        }
        if classification.cancel_leader {
            self.leader.cancel();
        }
        self.execute_intent(classification.intent, event, tx)
    }

    fn execute_intent(
        &mut self,
        intent: EditorIntent,
        event: &InputEvent,
        tx: &AppTx,
    ) -> EventState {
        match intent {
            EditorIntent::Consume => EventState::Consumed,
            EditorIntent::EditorPaste => {
                if !self.try_paste_image(tx)
                    && let InputEvent::Paste(text) = event
                    && !text.is_empty()
                    && let Some(ed) = self.panels.editor_mut()
                {
                    ed.paste_text(text, tx);
                }
                EventState::Consumed
            }
            EditorIntent::ImageProbe => {
                if self.try_paste_image(tx) {
                    EventState::Consumed
                } else {
                    // No image: the rest of the ladder decides. Reclassify
                    // the tail against fresh state — any leader cancel was
                    // already applied by the probe classification, so the
                    // tail must not re-cancel (`cancel_leader = false`).
                    // A key path (Ctrl+V): no press to pair, so no double.
                    let ctx = self.input_ctx(false);
                    let classification = {
                        let s = self.settings.read().unwrap();
                        crate::app_screen::editor_input::classify_tail(
                            event,
                            &s.key_bindings,
                            &ctx,
                            false,
                        )
                    };
                    self.apply_classification(classification, event, tx)
                }
            }
            EditorIntent::FollowLink => {
                if self.follow_link_at_cursor(tx) {
                    EventState::Consumed
                } else if matches!(event, InputEvent::Mouse(_)) {
                    // Nothing under the cursor to follow, and this arrived as a
                    // press. Swallowing it would make the second click of a
                    // double a silent no-op anywhere but on a link, and would
                    // claim the gesture buffer-wide for a follow that did not
                    // happen. Hand it back to the panels as the press it is —
                    // the same fallback-on-runtime-outcome shape `ImageProbe`
                    // uses when the clipboard turns out to hold no image.
                    self.execute_intent(EditorIntent::Mouse, event, tx)
                } else {
                    EventState::Consumed
                }
            }
            EditorIntent::LeaderKey(key) => self.handle_leader_key(&key, tx),
            EditorIntent::LeaderStart => {
                self.leader.start();
                self.schedule_whichkey_reveal(tx);
                EventState::Consumed
            }
            EditorIntent::Op(op) => {
                self.run_op(op, tx);
                EventState::Consumed
            }
            EditorIntent::ToggleOverlay { kind, open } => {
                if self.overlays.active_kind() == Some(kind) {
                    self.dismiss_overlay();
                } else {
                    self.open_overlay(open, tx);
                }
                EventState::Consumed
            }
            EditorIntent::OpenOverlay(open) => {
                self.open_overlay(open, tx);
                EventState::Consumed
            }
            EditorIntent::Overlay => self.overlays.handle_input(event, tx),
            EditorIntent::Mouse => {
                // `PanelSet` hit-tests the panel columns: a click focuses the
                // panel under the cursor (one rule for every panel) and the
                // event is forwarded to that panel for its internal behavior.
                let state = self.panels.handle_mouse(event, tx);
                // Ask clicks (turn select, citation) move the drawer's Sources.
                self.ask.sync_sources(&mut self.panels, tx);
                // A selectionless right-click in the editor asks for the
                // note's context menu — the screen owns the path, so it
                // opens it here.
                if self.panels.editor().is_some_and(|e| e.wants_context_menu) {
                    if let Some(ed) = self.panels.editor_mut() {
                        ed.wants_context_menu = false;
                    }
                    tx.send(AppEvent::FileOp(FileOp::ShowMenu(self.path.clone())))
                        .ok();
                }
                state
            }
            EditorIntent::Panel { fallback } => {
                let state = self.panels.handle_input(event, tx);
                // Ask keys (j/k select, i/composer, submit) move the drawer's
                // Sources in step with the thread's selected turn.
                self.ask.sync_sources(&mut self.panels, tx);
                if state == EventState::NotConsumed {
                    match fallback {
                        PanelFallback::None => state,
                        PanelFallback::FocusCycle(CycleDir::Right) => {
                            self.focus_right(tx);
                            EventState::Consumed
                        }
                        PanelFallback::FocusCycle(CycleDir::Left) => {
                            self.focus_left(tx);
                            EventState::Consumed
                        }
                        PanelFallback::FocusEditor => {
                            self.focus_editor();
                            EventState::Consumed
                        }
                    }
                } else {
                    state
                }
            }
        }
    }

    fn run_op(&mut self, op: EditorOp, tx: &AppTx) {
        match op {
            EditorOp::ToggleDrawer => self.toggle_drawer(tx),
            EditorOp::FocusLeft => self.focus_left(tx),
            EditorOp::FocusRight => self.focus_right(tx),
            EditorOp::OpenJournal => {
                tx.send(AppEvent::OpenJournal).ok();
            }
            EditorOp::ShowFileOps => {
                tx.send(AppEvent::FileOp(FileOp::ShowMenu(self.path.clone())))
                    .ok();
            }
            EditorOp::ToggleQueryPanel => self.toggle_backlinks(tx),
            EditorOp::OpenFileBrowserReveal => {
                self.open_drawer_view(DrawerView::Files, tx);
                self.reveal_note_dir_in_sidebar(tx);
            }
            EditorOp::SaveCurrentQuery => {
                if let Some((query, provenance, source)) = self.save_query_source() {
                    // Opening the save dialog replaces the note browser (if
                    // any); the chained-open guard preserves the original
                    // opener focus.
                    self.present_overlay(Box::new(ActiveDialog::save_search(
                        query,
                        provenance,
                        source,
                        self.vault.clone(),
                        tx,
                    )));
                }
            }
            EditorOp::FindInBuffer => {
                if let Some(ed) = self.panels.editor_mut() {
                    ed.open_or_advance_search();
                }
            }
            EditorOp::ReplaceInBuffer => {
                if let Some(ed) = self.panels.editor_mut() {
                    ed.open_replace();
                }
            }
            EditorOp::ApplyText(text_action) => {
                if let Some(ed) = self.panels.editor_mut() {
                    ed.apply_text_action(text_action);
                }
            }
            EditorOp::OpenAsk => self.open_ask_workspace(tx),
        }
    }

    /// The one door for every overlay the screen can open: guard (no overlay
    /// over an open overlay), build the recipe, present it. Opens that need
    /// more than construction (the Ask workspace's capability gate, drawer
    /// views) are not overlays and keep their own methods.
    fn open_overlay(&mut self, open: OverlayOpen, tx: &AppTx) {
        if self.overlays.is_open() {
            return;
        }
        let overlay = self.build_overlay(open, tx);
        self.present_overlay(overlay);
    }

    /// Construction recipes for [`OverlayOpen`] — the single site answering
    /// "what overlays exist and how is each built". Reads screen state (vault,
    /// settings, open note, panel sort/order seeds) but never mutates it;
    /// presentation and the open-guard live in [`Self::open_overlay`].
    fn build_overlay(&self, open: OverlayOpen, tx: &AppTx) -> Box<dyn Overlay> {
        let s = self.settings.read().unwrap();
        match open {
            // The note-browser modal over the full-text search provider
            // (Ctrl-K and the leader's find paths).
            OverlayOpen::SearchBrowser => {
                let provider = resolving_search_source(
                    self.vault.clone(),
                    s.current_last_paths(),
                    Some(self.path.clone()),
                );
                Box::new(NoteBrowserModal::new(
                    "Note Browser",
                    BrowserScope::Query,
                    provider,
                    self.vault.clone(),
                    s.key_bindings.clone(),
                    s.icons(),
                    tx.clone(),
                ))
            }
            // The note-browser modal over the fuzzy file finder (Ctrl-O and
            // the leader's `f f`).
            OverlayOpen::FileFinder => {
                let current_dir = self.path.get_parent_path().0;
                let provider = FileFinderProvider::new(self.vault.clone(), current_dir);
                Box::new(NoteBrowserModal::new(
                    "Find Note",
                    BrowserScope::Files,
                    provider,
                    self.vault.clone(),
                    s.key_bindings.clone(),
                    s.icons(),
                    tx.clone(),
                ))
            }
            // F3 and leader `f s`.
            OverlayOpen::SavedSearches => Box::new(SavedSearchesModal::new(
                self.vault.clone(),
                s.key_bindings.clone(),
                s.icons(),
                tx.clone(),
            )),
            // Ctrl+Shift+P and leader `p`.
            OverlayOpen::CommandPalette => {
                let gateway = s
                    .key_bindings
                    .first_combo_for(&ActionShortcuts::Leader)
                    .unwrap_or_else(|| "leader".to_string());
                Box::new(
                    crate::components::command_palette::CommandPaletteModal::new(
                        &s.leader_tree(),
                        &gateway,
                        s.icons(),
                        tx.clone(),
                    ),
                )
            }
            // SwitchWorkspace action and leader `v s`.
            OverlayOpen::WorkspaceSwitcher => Box::new(ActiveDialog::workspace_switcher(&s)),
            // Leader `v t` and inside CFG via `t`; the full settings screen
            // stays on the OpenSettings binding.
            OverlayOpen::ThemePicker => Box::new(ActiveDialog::theme_picker(&s)),
            OverlayOpen::Help => Box::new(ActiveDialog::help(&s.key_bindings)),
            OverlayOpen::QueryHelp => Box::new(ActiveDialog::query_syntax()),
            OverlayOpen::Cheatsheet => Box::new(ActiveDialog::cheatsheet(&s)),
            OverlayOpen::SortQuery => {
                let (field, order) = self.panels.query().current_order();
                Box::new(ActiveDialog::sort(SortTarget::Query, field, order, false))
            }
            OverlayOpen::SortSidebar => {
                let (field, order) = self.panels.sidebar().current_sort();
                Box::new(ActiveDialog::sort(
                    SortTarget::Sidebar,
                    field,
                    order,
                    self.panels.sidebar().group_dirs(),
                ))
            }
            OverlayOpen::QuickNote => Box::new(ActiveDialog::quick_note(self.vault.clone())),
        }
    }

    /// One owner for the self-update lifecycle's display half; the
    /// app-global half (persisting dismissals, seeding later screens) lives
    /// in the App loop (`app::handle_app_message`).
    fn handle_update(&mut self, flow: UpdateFlow, tx: &AppTx) {
        match flow {
            UpdateFlow::Available(status) => {
                self.update = Some(status);
            }
            UpdateFlow::ShowDialog => {
                if let Some(status) = self.update.clone() {
                    self.present_overlay(Box::new(ActiveDialog::update(&status)));
                }
            }
            UpdateFlow::Dismiss(_) => {
                // Persistence happens in main; here we just drop the indicator.
                self.update = None;
            }
            UpdateFlow::Applied => {
                // Installed — drop the notice so the footer/dialog stop offering
                // the version we just wrote (restart still required to run it).
                self.update = None;
            }
            UpdateFlow::Apply => {
                let tx2 = tx.clone();
                tx.send(AppEvent::FlashMessage("Downloading update…".into()))
                    .ok();
                tokio::spawn(async move {
                    let result = async {
                        let latest = crate::update::latest_release().await?;
                        crate::update::install(latest).await
                    }
                    .await;
                    let msg = match result {
                        Ok(()) => {
                            tx2.send(AppEvent::Update(UpdateFlow::Applied)).ok();
                            "Update installed — restart kimün to apply".to_string()
                        }
                        Err(e) => format!("Update failed: {e}"),
                    };
                    tx2.send(AppEvent::FlashMessage(msg)).ok();
                });
            }
        }
    }

    /// One owner for file operations: requests present the matching dialog,
    /// confirmations keep the sidebar and the open note in step.
    async fn handle_file_op(&mut self, op: FileOp, tx: &AppTx) {
        match op {
            FileOp::ShowMenu(path) => {
                self.present_overlay(Box::new(ActiveDialog::file_ops_menu(path)));
            }
            FileOp::ShowDelete(path) => {
                self.present_overlay(Box::new(ActiveDialog::delete(path, self.vault.clone())));
            }
            FileOp::ShowRename(path) => {
                self.present_overlay(Box::new(ActiveDialog::rename(path, self.vault.clone())));
            }
            FileOp::ShowMove(path) => {
                self.present_overlay(Box::new(ActiveDialog::move_to(
                    path,
                    self.vault.clone(),
                    tx,
                )));
            }
            FileOp::ShowCreateWithContent { path, content } => {
                // The suggested path is derived from a title (an Ask question),
                // so unlike the other create-note entry points it is not known
                // to be free — and the create behind this dialog avoids
                // conflicts by incrementing the name. Resolve that name here so
                // the dialog shows the note the user is actually confirming,
                // instead of promising `ask/foo.md` and quietly writing
                // `ask/foo_0.md`.
                let path = self.vault.free_note_path(&path).await;
                self.present_overlay(Box::new(ActiveDialog::create_note(
                    path,
                    self.vault.clone(),
                    Some(content),
                )));
            }
            FileOp::Created(path) => {
                // Pure notification: a note now exists at `path`. Opening is the
                // creator's job (via OpenPath); here we only keep the sidebar in
                // step when it is browsing the new note's directory.
                self.refresh_sidebar_if_showing(&path.get_parent_path().0, tx);
            }
            FileOp::Deleted(path) => {
                self.on_entry_op(path, tx).await;
            }
            FileOp::Renamed { from, to } => {
                // Note rename → targeted row update (and retarget the editor if
                // it is the open note). Directory rename keeps the full reload.
                if from.is_note() {
                    self.on_note_renamed(from, to, tx).await;
                } else {
                    self.on_entry_op(from, tx).await;
                }
            }
            FileOp::Moved { from, .. } => {
                self.on_entry_op(from, tx).await;
            }
        }
    }

    /// One owner for the saved-search save/select flow.
    fn handle_saved_search(&mut self, flow: SavedSearchFlow, tx: &AppTx) {
        match flow {
            SavedSearchFlow::Selected { query, name } => {
                // Deliberate non-restoring close: the selection lands in the
                // Query panel (set by apply_saved_search), not back on the
                // overlay's opener — so close the overlay without dismiss_overlay.
                self.overlays.close();
                self.apply_saved_search(query, name, tx);
            }
            SavedSearchFlow::Confirmed {
                name,
                query,
                source,
            } => {
                // Write in the background; the breadcrumb re-pin waits for
                // the success event so the UI never claims an unpersisted
                // save (see `Persisted` below).
                let vault = self.vault.clone();
                let tx = tx.clone();
                tokio::spawn(async move {
                    match vault.save_search(&name, &query).await {
                        Ok(()) => {
                            tx.send(AppEvent::SavedSearch(SavedSearchFlow::Persisted {
                                name,
                                query,
                                source,
                            }))
                            .ok();
                        }
                        Err(e) => {
                            tracing::warn!("failed to save search '{}': {}", name, e);
                            tx.send(AppEvent::SavedSearch(SavedSearchFlow::SaveFailed { name }))
                                .ok();
                        }
                    }
                });
            }
            // Re-pin the panel breadcrumb to the saved identity: the edited
            // marker drops on an update, the name switches on a save-as-new.
            // Only for panel-sourced saves (a note-browser save must not
            // steal the panel's provenance, even when the query text
            // coincides), and not for the query-as-name fallback (a
            // breadcrumb that echoes the query is noise).
            SavedSearchFlow::Persisted {
                name,
                query,
                source: SaveSource::QueryPanel,
            } if name.trim() != query.trim() => {
                self.panels.query_mut().repin_saved_search(name, &query);
            }
            SavedSearchFlow::Persisted { .. } => {}
            SavedSearchFlow::SaveFailed { name } => {
                self.footer
                    .flash(format!("Failed to save search '{name}'"), tx);
            }
        }
    }

    /// The editor-owned singles: everything with exactly one arm and no
    /// family. Family events never reach this match.
    async fn handle_owned_message(&mut self, msg: AppEvent, tx: &AppTx) {
        match msg {
            AppEvent::RagStatus(status) => {
                let ask_was = self.rag_status.llm_available();
                let sem_was = self.rag_status.search_available();
                self.rag_status = status;
                // Both rail entries are live-status-driven: ASK on whether the
                // server can answer questions, SEM on whether it can search.
                // Rebuild the rail when either flips (an active view
                // stays put when its capability drops — only the rail entry
                // goes). The Ask client only needs refreshing on the ASK flip.
                let ask_now = status.llm_available();
                let sem_now = status.search_available();
                if ask_was != ask_now || sem_was != sem_now {
                    let (kb, icons) = {
                        let s = self.settings.read().unwrap();
                        (s.key_bindings.clone(), s.icons())
                    };
                    self.panels.rebuild_rail(
                        kb,
                        icons,
                        crate::components::activity_rail::RailCaps {
                            semantic: sem_now,
                            ask: ask_now,
                        },
                    );
                }
                if ask_was != ask_now {
                    self.ask
                        .refresh_capability(&mut self.panels, self.rag_status)
                        .await;
                }
            }
            AppEvent::Ask(data) => self.ask.handle_data(&mut self.panels, data, tx),
            // Stale completions (for notes we've navigated away from) fall
            // through to the catch-all and are dropped.
            AppEvent::FlashMessage(msg) => {
                self.footer.flash(msg, tx);
            }
            AppEvent::ExecuteLeaderAction(action) => {
                if self.overlays.is_open() {
                    // The palette closes itself before sending, so this is
                    // unreachable from it — but never drop an action silently.
                    tracing::warn!("ExecuteLeaderAction({action:?}) dropped: overlay open");
                } else {
                    self.execute_leader_action(action, tx);
                }
            }
            AppEvent::ApplyTheme { theme, persist } => {
                // The picker resolved the theme already — no disk re-read,
                // just adapt to the terminal and swap.
                {
                    let mut s = self.settings.write().unwrap();
                    s.set_theme(theme.name.clone());
                }
                self.theme = (*theme).adapt_to_terminal();
                if persist {
                    let snapshot = self.settings.read().unwrap().clone();
                    tokio::spawn(async move {
                        snapshot.save_to_disk().ok();
                    });
                }
                tx.send(AppEvent::Redraw).ok();
            }
            // Drawer panels can't emit these under an overlay, but guard
            // anyway: never mutate panels while an overlay owns input.
            AppEvent::RunTagQuery(label) if !self.overlays.is_open() => {
                self.open_find_with_query(format!("#{label}"), None, tx);
            }
            AppEvent::JumpToHeading(heading) if !self.overlays.is_open() => {
                if let Some(ed) = self.panels.editor_mut() {
                    ed.jump_to_heading(&heading);
                }
                self.focus_editor();
            }
            AppEvent::OpenDrawerView(view) => {
                // The rail hides SEM unless the server is reachable for search,
                // but the leader path (`drawer.semantic`) can still request it —
                // gate here so every route gets the same answer.
                if view == DrawerView::Semantic && !self.rag_status.search_available() {
                    let msg = if crate::rag::rag_configured(&self.settings) {
                        "Semantic search needs a reachable server with an embedder"
                    } else {
                        "Set kimun_server_url in config to use semantic search"
                    };
                    tx.send(AppEvent::FlashMessage(msg.into())).ok();
                }
                // ASK needs an LLM-configured server (the rail hides its entry
                // otherwise); gate every route the same way.
                else if view == DrawerView::Ask && !self.rag_status.llm_available() {
                    tx.send(AppEvent::FlashMessage(
                        "Ask needs an LLM-configured server; this one is semantic-search only"
                            .into(),
                    ))
                    .ok();
                }
                // Selecting the already-active view toggles the drawer closed
                // (spec §3: clicking the active rail item toggles).
                else if self.panels.is_visible(PanelKind::Drawer)
                    && self.panels.active_drawer_view() == view
                {
                    self.panels.hide(PanelKind::Drawer);
                } else {
                    self.open_drawer_view(view, tx);
                }
            }
            AppEvent::CloseOverlay => {
                // Dismiss-to-opener. Guarded by is_open() on purpose: a
                // selection that wants a specific post-close focus
                // (OpenPath -> editor, SavedSearchSelected -> Query panel)
                // closes the overlay itself first, so a later/!dialog
                // CloseOverlay must not re-restore and clobber that focus.
                self.dismiss_overlay();
            }
            AppEvent::SortChanged {
                target,
                field,
                order,
                group_directories,
                persist,
            } => {
                match target {
                    SortTarget::Sidebar if persist => {
                        // Update the sidebar's in-session per-context default AND
                        // apply live. `is_current_journal()` is the single source
                        // of truth for which context this save targets — reused
                        // for the on-disk settings write below.
                        let is_journal = self.panels.sidebar().is_current_journal();
                        self.panels
                            .sidebar_mut()
                            .save_default(field, order, group_directories);
                        {
                            let mut s = self.settings.write().unwrap();
                            if is_journal {
                                s.journal_sort_field =
                                    crate::settings::SortFieldSetting::from(field);
                                s.journal_sort_order =
                                    crate::settings::SortOrderSetting::from(order);
                            } else {
                                s.default_sort_field =
                                    crate::settings::SortFieldSetting::from(field);
                                s.default_sort_order =
                                    crate::settings::SortOrderSetting::from(order);
                            }
                            s.group_directories = group_directories;
                        }
                        let snapshot = self.settings.read().unwrap().clone();
                        tokio::spawn(async move {
                            snapshot.save_to_disk().ok();
                        });
                    }
                    SortTarget::Sidebar => {
                        self.panels
                            .sidebar_mut()
                            .apply_sort(field, order, group_directories)
                    }
                    // The query panel has no persisted default (the order lives
                    // in the query string); `persist` is always false here.
                    SortTarget::Query => self.panels.query_mut().apply_sort(field, order, tx),
                }
            }
            AppEvent::Autosave => {
                self.spawn_autosave(tx);
            }
            AppEvent::AutosaveCompleted {
                path,
                saved_revision,
                title,
            } => {
                if path == self.path
                    && let Some(rev) = saved_revision
                    && let Some(ed) = self.panels.editor_mut()
                {
                    ed.mark_saved_at_revision(rev);
                }
                if let Some(raw_title) = title {
                    self.note_saved(&path, raw_title);
                }
                // The write changed the working tree — refresh the git
                // segment (throttled).
                self.doc_meta.refresh_git(tx);
                // `SingleSlotTask::is_in_flight()` flips to false the
                // moment the spawned future returns (success or panic),
                // so we don't have to clear the slot manually here —
                // the next `spawn_autosave` tick will overwrite it.
                // Skip explicit cleanup; was previously racy because a
                // stale completion arriving after `try_save` had
                // already cleared and respawned could wipe the fresh
                // handle.
            }
            AppEvent::FocusSidebar => {
                self.focus_sidebar(tx);
            }
            AppEvent::FollowLink(target) => {
                self.follow_link(target, tx).await;
            }
            AppEvent::FollowLabel(name) => {
                let initial = format!("#{name}");
                let s = self.settings.read().unwrap();
                let provider = resolving_search_source(
                    self.vault.clone(),
                    s.current_last_paths(),
                    Some(self.path.clone()),
                );
                let modal = NoteBrowserModal::with_initial_query(
                    "Note Browser",
                    BrowserScope::Query,
                    provider,
                    self.vault.clone(),
                    s.key_bindings.clone(),
                    s.icons(),
                    tx.clone(),
                    initial,
                );
                drop(s);
                self.present_overlay(Box::new(modal));
            }
            AppEvent::InsertAtCursor(text) if self.panels.focused() == PanelKind::Editor => {
                if let Some(ed) = self.panels.editor_mut() {
                    ed.insert_at_cursor(&text, tx);
                }
            }
            _ => {}
        }
    }

    pub fn focus_editor(&mut self) {
        self.panels.focus(PanelKind::Editor);
    }

    /// Whether the drawer is open showing `view`.
    fn drawer_open_on(&self, view: DrawerView) -> bool {
        self.panels.is_visible(PanelKind::Drawer) && self.panels.active_drawer_view() == view
    }

    /// Reflect the currently-open note (`self.path`) into whichever drawer view
    /// is visible (FIND/LINKS/OUTLINE). Shared by `open_path` and
    /// `on_note_renamed` so a rename keeps the drawers in step, not just a
    /// fresh open.
    fn reflect_open_note_in_drawers(&mut self, tx: &AppTx) {
        let path = self.path.clone();
        if self.drawer_open_on(DrawerView::Find) {
            self.panels.query_mut().set_note(path.clone(), tx.clone());
        }
        if self.panels.is_visible(PanelKind::Drawer) {
            match self.panels.active_drawer_view() {
                DrawerView::Links => self.panels.links_mut().set_note(path.clone(), tx),
                DrawerView::Outline => self.panels.outline_mut().set_note(path, tx),
                _ => {}
            }
        }
    }

    /// Point the sidebar at the current note's directory. Skips the engine
    /// rebuild when the sidebar is already there so an in-progress filter
    /// and selection survive a re-open.
    fn reveal_note_dir_in_sidebar(&mut self, tx: &AppTx) {
        let note_parent = self.path.get_parent_path().0;
        if self.panels.sidebar().is_empty()
            || !note_parent.is_like(self.panels.sidebar().current_dir())
        {
            self.navigate_sidebar(note_parent, tx);
        }
    }

    /// Focus the drawer, revealing it on FILES if hidden — but never clobber
    /// the view the user already has open (e.g. a FIND query in progress).
    /// Sent by the nvim backend's leave-editor motions.
    pub fn focus_sidebar(&mut self, tx: &AppTx) {
        if !self.panels.is_visible(PanelKind::Drawer) {
            // Routed through the host opener so the FILES view reveals the
            // current note's directory like any other drawer open (it also
            // focuses the drawer).
            self.open_drawer_view(DrawerView::Files, tx);
        } else {
            self.panels.focus(PanelKind::Drawer);
        }
    }

    /// Switch the drawer to `view`, reveal it, and focus it. The per-view
    /// reveal side effects live in `drawer_view_revealed` (the heavy work
    /// that keeps the reveal in the host rather than in `PanelSet`).
    fn open_drawer_view(&mut self, view: DrawerView, tx: &AppTx) {
        // Keep the editor-area Ask content in lockstep with the drawer view:
        // entering ASK restores the stashed thread; leaving it stashes the
        // live one (rules 1 & 2 — thread survives every view switch).
        self.ask.transition(&mut self.panels, view, tx);
        let newly_shown = !self.drawer_open_on(view);
        self.panels.open_drawer_view(view);
        self.drawer_view_revealed(view, newly_shown, tx);
        // The ASK workspace lives in the editor area; drop the user on the
        // composer rather than the Sources drawer. Every other view focuses
        // the drawer as before.
        if view == DrawerView::Ask {
            self.panels.focus(PanelKind::Editor);
        } else {
            self.panels.focus(PanelKind::Drawer);
        }
    }

    /// Ensure the Ask workspace is the editor-area content, for the leader
    /// `a` conversation actions. Ungated: managing an existing thread works
    /// even when the server can't answer (the composer stays disabled).
    fn ensure_ask_workspace(&mut self, tx: &AppTx) {
        if !self.panels.is_showing_ask() {
            self.open_drawer_view(DrawerView::Ask, tx);
        }
    }

    /// Ensure the Ask workspace is showing, then run `f` against its live
    /// panel — the shared shape behind the leader `a n`/`a y`/`a e`/`a r`
    /// conversation actions.
    fn with_ask_panel(&mut self, tx: &AppTx, f: impl FnOnce(&mut ThreadPanel, &AppTx)) {
        self.ensure_ask_workspace(tx);
        f(self.panels.ask_mut(), tx);
    }

    /// Per-view side effects to run when `view` becomes visible in the
    /// drawer — the single table shared by every reveal path (rail/leader
    /// opens, the Ctrl-T toggle restore) so a view cannot go stale on one
    /// path and refresh on another. `newly_shown` gates the effects that
    /// must not clobber state the user already has on screen (an
    /// in-progress FIND query, a browsed sidebar directory); the rest
    /// refresh unconditionally. Never touches focus — callers decide that.
    fn drawer_view_revealed(&mut self, view: DrawerView, newly_shown: bool, tx: &AppTx) {
        match view {
            DrawerView::Find if newly_shown => {
                self.panels
                    .query_mut()
                    .set_note(self.path.clone(), tx.clone());
            }
            DrawerView::Files if newly_shown => {
                self.reveal_note_dir_in_sidebar(tx);
            }
            DrawerView::Config => {
                let info = {
                    let s = self.settings.read().unwrap();
                    let key_of = |a: &ActionShortcuts| {
                        s.key_bindings
                            .first_combo_for(a)
                            .unwrap_or_else(|| "unbound".to_string())
                    };
                    crate::components::drawer::ConfigInfo {
                        theme_name: s.get_theme().name,
                        leader_key: key_of(&ActionShortcuts::Leader),
                        preferences_key: key_of(&ActionShortcuts::OpenPreferences),
                        leader_timeout_ms: s.leader_timeout_ms,
                        config_path: s
                            .config_file
                            .as_ref()
                            .map(|p| p.display().to_string())
                            .unwrap_or_else(|| "default location".to_string()),
                    }
                };
                self.panels.drawer_set_config_info(info);
            }
            DrawerView::Semantic => self.panels.semantic_mut().ensure_source(tx),
            DrawerView::Tags => self.panels.tags_mut().refresh(tx),
            DrawerView::Links => self.panels.links_mut().set_note(self.path.clone(), tx),
            DrawerView::Outline => self.panels.outline_mut().set_note(self.path.clone(), tx),
            _ => {}
        }
    }

    /// Move focus one visible panel left, wrapping at the end.
    fn focus_left(&mut self, _tx: &AppTx) {
        if let Some(kind) = self.panels.prev_kind() {
            self.panels.focus(kind);
        }
    }

    /// Move focus one visible panel right, wrapping at the end.
    fn focus_right(&mut self, _tx: &AppTx) {
        if let Some(kind) = self.panels.next_kind() {
            self.panels.focus(kind);
        }
    }

    /// Toggle the drawer (Ctrl-T): hiding it gives the full remaining width
    /// to the editor; showing it restores the last view. Restoring is a
    /// fresh reveal: the restored view re-targets/refreshes via the shared
    /// `drawer_view_revealed` table — the note (or its data) may have
    /// changed while hidden. Unlike an explicit open, toggling never moves
    /// focus into the drawer.
    fn toggle_drawer(&mut self, tx: &AppTx) {
        if self.panels.is_visible(PanelKind::Drawer) {
            self.panels.hide(PanelKind::Drawer);
        } else {
            self.panels.show(PanelKind::Drawer);
            self.drawer_view_revealed(self.panels.active_drawer_view(), true, tx);
        }
    }

    /// The query the save-current-query action would save, with its
    /// saved-search provenance (breadcrumb name) for the dialog's name
    /// pre-fill. Sourced from the active note browser if one is open (Ctrl+K
    /// modal), otherwise from the Query panel. `None` when there is nothing
    /// to save: a blank query, or another overlay is open.
    fn save_query_source(&self) -> Option<(String, Option<String>, SaveSource)> {
        let (query, provenance, source) = match self.overlays.active_kind() {
            Some(OverlayKind::NoteBrowser) => (
                self.overlays.active_query().unwrap_or_default().to_string(),
                self.overlays
                    .active_saved_search_provenance()
                    .map(str::to_string),
                SaveSource::NoteBrowser,
            ),
            None => (
                self.panels.query().active_query().to_string(),
                self.panels.query().saved_search_name().map(str::to_string),
                SaveSource::QueryPanel,
            ),
            Some(_) => return None,
        };
        if query.trim().is_empty() {
            None
        } else {
            Some((query, provenance, source))
        }
    }

    /// Schedule a redraw for when the which-key overlay should reveal: the
    /// hesitation timeout after the sequence (re)advanced. Fluent typing
    /// never sees the overlay; the timer redraw simply finds the sequence
    /// already gone.
    fn schedule_whichkey_reveal(&self, tx: &AppTx) {
        let timeout = {
            let s = self.settings.read().unwrap();
            std::time::Duration::from_millis(s.leader_timeout_ms)
        };
        let tx2 = tx.clone();
        tokio::spawn(async move {
            tokio::time::sleep(timeout + std::time::Duration::from_millis(10)).await;
            let _ = tx2.send(AppEvent::Redraw);
        });
    }

    /// Switch to the Ask workspace and drop the cursor on the composer (the
    /// Ask shortcut / leader `a a`). The rail hides the ASK entry when the
    /// server can't answer questions, so this shortcut is the only remaining
    /// way in — hence the `llm_available` gate. The gate only
    /// applies to that enter-from-outside path: when Ask is already showing,
    /// focusing the composer is ungated, matching the sibling `a n`/`a
    /// y`/`a e`/`a r` actions, which work fine on a degraded (capability-off)
    /// thread.
    fn open_ask_workspace(&mut self, tx: &AppTx) {
        if self.overlays.is_open() {
            return;
        }
        if !self.panels.is_showing_ask() {
            if !self.rag_status.llm_available() {
                tx.send(AppEvent::FlashMessage(
                    "Ask needs an LLM-configured server; this one is semantic-search only".into(),
                ))
                .ok();
                return;
            }
            self.open_drawer_view(DrawerView::Ask, tx);
        }
        self.panels.ask_mut().focus_composer();
        self.panels.focus(PanelKind::Editor);
    }

    /// Follow the **follow target** under the editor cursor (FollowLink action,
    /// Ctrl+Enter on kitty-protocol terminals).
    ///
    /// Returns whether anything was actually followed, so a caller that only
    /// *guessed* there was something there can fall back. A double-click is
    /// exactly that guess: the classifier cannot hit-test the buffer, so it
    /// asks and lets the answer decide.
    fn follow_link_at_cursor(&mut self, tx: &AppTx) -> bool {
        use crate::components::text_editor::FollowTarget;
        // In the attachment view, FollowLink (Ctrl+N) opens the attachment with
        // the OS default program rather than following a link (there is none).
        if self.panels.is_showing_attachment() {
            self.open_attachment_externally(tx);
            return true;
        }
        let Some(editor) = self.panels.editor_mut() else {
            return false;
        };
        match editor.follow_target_at_cursor() {
            Some(FollowTarget::Link(target)) => {
                tx.send(AppEvent::FollowLink(target)).ok();
                true
            }
            Some(FollowTarget::Label(name)) => {
                tx.send(AppEvent::FollowLabel(name)).ok();
                true
            }
            None => false,
        }
    }

    /// Opens the attachment currently shown in the editor area with the OS
    /// default program (the same handoff `follow_link` uses for image links).
    fn open_attachment_externally(&mut self, tx: &AppTx) {
        let Some(path) = self.panels.attachment_path() else {
            return;
        };
        let os_path = self.vault.path_to_pathbuf(path);
        match open::that_detached(&os_path) {
            Ok(()) => self
                .footer
                .flash(format!("Opening {}", os_path.display()), tx),
            Err(e) => self.footer.flash(format!("Cannot open: {e}"), tx),
        }
    }

    /// One key of a pending leader sequence. Esc cancels (focus returns to
    /// the editor), Backspace steps up, chars walk the tree, a fired leaf
    /// executes. Everything is consumed — a pending sequence owns the
    /// keyboard.
    fn handle_leader_key(
        &mut self,
        key: &ratatui::crossterm::event::KeyEvent,
        tx: &AppTx,
    ) -> EventState {
        use ratatui::crossterm::event::{KeyCode, KeyModifiers};
        match key.code {
            KeyCode::Esc => {
                self.leader.cancel();
                self.focus_editor();
            }
            KeyCode::Backspace => {
                let outcome = self.leader.step_up();
                // Stepping past the root cancels — no reveal to re-arm then.
                if outcome == LeaderOutcome::SteppedUp {
                    self.schedule_whichkey_reveal(tx);
                }
            }
            KeyCode::Char(c) if !key.modifiers.contains(KeyModifiers::CONTROL) => {
                match self.leader.feed(c) {
                    LeaderOutcome::Fired(action) => self.execute_leader_action(action, tx),
                    LeaderOutcome::Invalid => {
                        // Gentle feedback; the sequence stays pending.
                        self.footer.flash(format!("leader: no entry for '{c}'"), tx);
                        self.schedule_whichkey_reveal(tx);
                    }
                    LeaderOutcome::Descended => self.schedule_whichkey_reveal(tx),
                    _ => {}
                }
            }
            // Other keys (arrows, function keys, …) are swallowed; the
            // sequence stays pending. Ctrl-chords never reach here — the
            // intercept in handle_input cancels and re-dispatches them.
            _ => {}
        }
        tx.send(AppEvent::Redraw).ok();
        EventState::Consumed
    }

    /// Execute a fired leader leaf. Stubs for surfaces that land in later
    /// phases flash a "coming soon" notice instead of silently doing nothing.
    fn execute_leader_action(&mut self, action: LeaderAction, tx: &AppTx) {
        match action {
            LeaderAction::OpenDrawer(view) => self.open_drawer_view(view, tx),

            LeaderAction::AppCheckUpdates => {
                if let Some(status) = self.update.clone() {
                    self.present_overlay(Box::new(ActiveDialog::update(&status)));
                } else {
                    // No cached notice — run a forced check and report the result.
                    let tx2 = tx.clone();
                    tx.send(AppEvent::FlashMessage("Checking for updates…".into()))
                        .ok();
                    tokio::spawn(async move {
                        let Ok(config_dir) = crate::settings::config_dir() else {
                            return;
                        };
                        match crate::update::check_now(config_dir, true).await {
                            Ok(Some(status)) if status.update_available => {
                                // Manual check: surface the notice AND open the
                                // dialog the user explicitly asked for (shown even
                                // if previously skipped — they asked).
                                tx2.send(AppEvent::Update(UpdateFlow::Available(status)))
                                    .ok();
                                tx2.send(AppEvent::Update(UpdateFlow::ShowDialog)).ok();
                            }
                            Ok(_) => {
                                tx2.send(AppEvent::FlashMessage("kimün is up to date".into()))
                                    .ok();
                            }
                            Err(e) => {
                                tx2.send(AppEvent::FlashMessage(format!(
                                    "Update check failed: {e}"
                                )))
                                .ok();
                            }
                        }
                    });
                }
            }

            // +find — list-style leaves route to today's pickers; the
            // telescope modal takes them over in phase 08.
            LeaderAction::FindFiles => self.open_overlay(OverlayOpen::FileFinder, tx),
            LeaderAction::FindGrep => self.open_overlay(OverlayOpen::SearchBrowser, tx),
            LeaderAction::FindTags => self.open_drawer_view(DrawerView::Tags, tx),
            LeaderAction::FindBacklinks => {
                self.open_find_with_query("<{note}".to_string(), None, tx)
            }
            LeaderAction::FindSaved => self.open_overlay(OverlayOpen::SavedSearches, tx),
            LeaderAction::FindRecent => self.open_overlay(OverlayOpen::SearchBrowser, tx),
            LeaderAction::FindHeadings => self.open_drawer_view(DrawerView::Outline, tx),

            // +note
            LeaderAction::NoteNew => {
                // The FILES filter doubles as the create field (typing a new
                // name offers "Create: …"); the telescope picker (08) gives
                // this a dedicated door.
                self.open_drawer_view(DrawerView::Files, tx);
                self.footer
                    .flash("type a name — Enter creates".to_string(), tx);
            }
            LeaderAction::NoteDaily => {
                tx.send(AppEvent::OpenJournal).ok();
            }
            LeaderAction::NoteFromTemplate => {
                self.footer.flash("templates — coming soon".to_string(), tx);
            }
            LeaderAction::NoteRename => {
                tx.send(AppEvent::FileOp(FileOp::ShowRename(self.path.clone())))
                    .ok();
            }
            LeaderAction::NoteMove => {
                tx.send(AppEvent::FileOp(FileOp::ShowMove(self.path.clone())))
                    .ok();
            }
            LeaderAction::NoteDelete => {
                tx.send(AppEvent::FileOp(FileOp::ShowDelete(self.path.clone())))
                    .ok();
            }

            // +links
            LeaderAction::LinksTab(tab) => {
                self.open_drawer_view(DrawerView::Links, tx);
                self.panels.links_mut().show_tab(tab, tx);
            }
            LeaderAction::LinksGraph => {
                self.footer
                    .flash("local graph — coming soon".to_string(), tx);
            }

            // +git/sync — status is live; the rest are display-only stubs
            // (spec §12 keeps git interactions out of scope).
            LeaderAction::GitStatus => {
                self.doc_meta.refresh_git(tx);
                let msg = self
                    .doc_meta
                    .git()
                    .cloned()
                    .unwrap_or_else(|| "not a git repository".to_string());
                self.footer.flash(msg, tx);
            }
            LeaderAction::GitSync | LeaderAction::GitLog | LeaderAction::GitDiff => {
                self.footer
                    .flash("git is display-only for now".to_string(), tx);
            }

            // +vault
            LeaderAction::VaultSwitch => self.open_overlay(OverlayOpen::WorkspaceSwitcher, tx),
            LeaderAction::VaultReindex => {
                // Fast reindex right here — the same pipeline the Settings
                // screen runs, result surfaced as a footer flash.
                let vault = self.vault.clone();
                let tx2 = tx.clone();
                self.footer.flash("reindexing…".to_string(), tx);
                tokio::spawn(async move {
                    let started = std::time::Instant::now();
                    let result = vault.index_notes(kimun_core::NotesValidation::Fast).await;
                    let msg = match result {
                        Ok(_) => format!("reindexed in {:.1?}", started.elapsed()),
                        Err(e) => format!("reindex failed: {e}"),
                    };
                    tx2.send(AppEvent::FlashMessage(msg)).ok();
                });
            }
            // `v c` opens the config panel (the CFG drawer); `v t` opens the
            // theme picker directly (also reachable inside CFG via `t`).
            LeaderAction::VaultConfig => self.open_drawer_view(DrawerView::Config, tx),
            LeaderAction::VaultTheme => self.open_overlay(OverlayOpen::ThemePicker, tx),
            LeaderAction::VaultPreferences => {
                tx.send(AppEvent::OpenScreen(ScreenEvent::OpenPreferences))
                    .ok();
            }
            LeaderAction::AppOnboarding => {
                tx.send(AppEvent::OpenScreen(ScreenEvent::OpenOnboarding))
                    .ok();
            }

            // +window
            LeaderAction::WindowZen => {
                self.panels.hide(PanelKind::Drawer);
                self.focus_editor();
            }
            LeaderAction::WindowSplit => {
                self.footer
                    .flash("editor splits — coming soon".to_string(), tx);
            }
            LeaderAction::WindowGrowDrawer => self.panels.adjust_drawer_width(4),
            LeaderAction::WindowShrinkDrawer => self.panels.adjust_drawer_width(-4),

            // +this note
            LeaderAction::NoteToggleTodo => {
                self.footer
                    .flash("toggle todo — coming soon".to_string(), tx);
            }
            LeaderAction::NotePreview => {
                self.footer
                    .flash("preview — lands with phase 09".to_string(), tx);
            }
            LeaderAction::NoteCopyWikilink => {
                let link = format!("[[{}]]", self.path.get_clean_name());
                crate::components::yank(link, "wikilink copied", tx);
            }
            LeaderAction::NoteExport => {
                self.footer.flash("export — coming soon".to_string(), tx);
            }
            LeaderAction::NoteYankPath => {
                let path = self.path.to_string();
                crate::components::yank(path, "note path copied", tx);
            }

            // +ask — the Ask workspace's conversation actions.
            LeaderAction::AskFocus => self.open_ask_workspace(tx),
            LeaderAction::AskNew => {
                self.with_ask_panel(tx, |panel, _tx| {
                    panel.thread_mut().clear();
                    panel.focus_composer();
                });
                self.panels.ask_sources_mut().reset(tx);
            }
            LeaderAction::AskCopy => {
                self.with_ask_panel(tx, |panel, tx| panel.copy_selected(tx));
            }
            LeaderAction::AskSave => {
                self.with_ask_panel(tx, |panel, tx| panel.save_selected(tx));
            }
            LeaderAction::AskRegenerate => {
                self.with_ask_panel(tx, |panel, tx| panel.regenerate_selected(tx));
                self.ask.sync_sources(&mut self.panels, tx);
            }
            LeaderAction::AskSource => {
                self.ensure_ask_workspace(tx);
                // The top source of the selected turn — sync the drawer to the
                // current turn first, then open its first source in the reader.
                self.ask.sync_sources_from_selected(&mut self.panels, tx);
                self.panels.ask_sources_mut().open_reader(0, tx);
                self.panels.focus(PanelKind::Drawer);
            }

            LeaderAction::Palette => self.open_overlay(OverlayOpen::CommandPalette, tx),
            LeaderAction::Help => self.open_overlay(OverlayOpen::Cheatsheet, tx),

            LeaderAction::NoteSave => {
                // Flush the periodic autosave immediately (no manual-save
                // concept; this force-persists the current buffer if dirty).
                self.spawn_autosave(tx);
            }
            LeaderAction::AppQuit => {
                tx.send(AppEvent::Quit).ok();
            }
        }
    }

    /// Kick off the async loads behind status line 2: the open note's
    /// backlink count and the workspace git summary. Results return as
    /// `BacklinkCountLoaded` / `GitStatusLoaded`; stale backlink completions
    /// are dropped by path. Contract: this runs when a note is *opened* (and
    /// the git half on autosave) — counts can go stale while a note stays
    /// open and another note adds a link to it; accepted for now.
    /// The one path that reveals FIND with a concrete query: used by saved
    /// searches and tag queries so they cannot drift on what "open FIND"
    /// means.
    fn open_find_with_query(&mut self, query: String, name: Option<String>, tx: &AppTx) {
        self.panels.open_drawer_view(DrawerView::Find);
        self.panels.query_mut().apply_query(query, name, tx.clone());
        self.panels.focus(PanelKind::Drawer);
    }

    fn apply_saved_search(&mut self, query: String, name: String, tx: &AppTx) {
        // The virtual backlinks entry's name should not override the
        // default "Backlinks" title — but the panel's title logic already
        // shows "Backlinks" whenever the active query is `<{note}`, so it's
        // safe to always pass the name through.
        self.open_find_with_query(query, Some(name), tx);
    }

    fn toggle_backlinks(&mut self, tx: &AppTx) {
        if self.drawer_open_on(DrawerView::Find) {
            self.panels.hide(PanelKind::Drawer);
        } else {
            self.open_drawer_view(DrawerView::Find, tx);
        }
    }
}

#[async_trait]
impl AppScreen for EditorScreen {
    fn get_kind(&self) -> ScreenKind {
        ScreenKind::Editor
    }

    async fn on_enter(&mut self, tx: &AppTx) {
        self.app_tx = Some(tx.clone());
        self.open_path(self.path.clone(), None, tx).await;
    }

    fn handle_input(&mut self, event: &InputEvent, tx: &AppTx) -> EventState {
        // Classify first, mutate after: the pure classifier resolves the
        // event against the input precedence (see `editor_input`), and the
        // executor methods below apply the resulting intent.
        //
        // The click run is fed ahead of the snapshot — it is the one piece of
        // input-relevant state the event itself advances, and the classifier
        // cannot advance it and stay pure. Nothing user-visible moves here.
        let double_click = self.track_click(event, std::time::Instant::now());
        let ctx = self.input_ctx(double_click);
        // The settings lock guards the key bindings, which only the
        // shortcut tier reads — never lock for mouse/paste traffic (mouse
        // motion is high-frequency).
        let classification = if matches!(event, InputEvent::Key(_)) {
            let s = self.settings.read().unwrap();
            classify(event, &s.key_bindings, &ctx)
        } else {
            classify(event, &KeyBindings::empty(), &ctx)
        };
        self.apply_classification(classification, event, tx)
    }

    fn render(&mut self, f: &mut ratatui::Frame) {
        let theme = &self.theme;
        f.render_widget(
            ratatui::widgets::Block::default().style(theme.base_style()),
            f.area(),
        );

        let rows = Layout::default()
            .direction(Direction::Vertical)
            .constraints([
                Constraint::Length(1),
                Constraint::Min(0),
                Constraint::Length(crate::components::footer_bar::STATUS_BAR_HEIGHT),
            ])
            .split(f.area());

        // ── Title bar (1 line): Kimün · note breadcrumb · workspace badge ──
        // Build the badge line once; its column width comes from the same
        // value that gets rendered, so glyph/separator tweaks can't drift.
        let workspace_badge = {
            let s = self.settings.read().unwrap();
            s.workspace_config.as_ref().map(|wc| {
                ratatui::text::Line::from(vec![
                    ratatui::text::Span::styled(
                        self.icons.workspace,
                        Style::default().fg(theme.accent.to_ratatui()),
                    ),
                    ratatui::text::Span::styled(
                        format!("  {}", wc.global.current_workspace),
                        Style::default().fg(theme.gray.to_ratatui()),
                    ),
                ])
            })
        };
        let workspace_label_width = workspace_badge
            .as_ref()
            .map(ratatui::text::Line::width)
            .unwrap_or_default();
        let breadcrumb = self
            .path
            .to_string()
            .trim_start_matches('/')
            .replace('/', " / ");
        let title_cols = Layout::default()
            .direction(Direction::Horizontal)
            .constraints([
                Constraint::Min(0),
                Constraint::Length(workspace_label_width as u16 + 2),
            ])
            .split(rows[0]);
        f.render_widget(
            Paragraph::new(ratatui::text::Line::from(vec![
                ratatui::text::Span::styled(
                    " Kimün ",
                    Style::default()
                        .fg(theme.accent.to_ratatui())
                        .add_modifier(ratatui::style::Modifier::BOLD),
                ),
                ratatui::text::Span::styled(
                    format!("─  {breadcrumb}"),
                    Style::default().fg(theme.fg_secondary.to_ratatui()),
                ),
            ])),
            title_cols[0],
        );
        if let Some(badge) = workspace_badge {
            f.render_widget(
                Paragraph::new(badge).alignment(ratatui::layout::Alignment::Right),
                title_cols[1],
            );
        }

        // The panels lay themselves out and render. No panel shows its
        // focused highlight while an overlay sits over them.
        self.panels
            .render(f, rows[1], theme, !self.overlays.is_open());

        // Status bar reflects the overlay if one is open, otherwise the
        // focused panel. `editing` drives the ⌨/≣ focus-context indicator —
        // true when a text field holds the cursor.
        let (focus_label, hints) = if let Some(kind) = self.overlays.active_kind() {
            (kind.label(), self.overlays.hint_shortcuts())
        } else {
            (self.panels.focused_label(), self.panels.focused_hints())
        };
        let editing = if let Some(kind) = self.overlays.active_kind() {
            // Browsers and the saved-searches modal host a query input;
            // dialogs are button/list selections.
            !matches!(kind, OverlayKind::Dialog)
        } else {
            match self.panels.focused() {
                PanelKind::Editor => true,
                PanelKind::Drawer => self.panels.drawer_is_text_input(),
                PanelKind::Rail => false,
            }
        };
        let path_str = self.path.to_string();
        // Link-under-cursor affordance (spec §5.2): `→ target · N backlinks`.
        // The backlink count loads async, cached per target.
        let link_segment = if self.panels.focused() == PanelKind::Editor && !self.overlays.is_open()
        {
            let link = self
                .panels
                .editor()
                .and_then(|e| e.follow_target_at_cursor());
            self.doc_meta
                .link_segment(link.as_ref(), &self.path, self.app_tx.as_ref())
        } else {
            None
        };
        // ln/col only when the editor buffer holds the cursor (not the
        // attachment view, which has none).
        let ln_col = (self.panels.focused() == PanelKind::Editor && !self.overlays.is_open())
            .then(|| {
                self.panels.editor().map(|e| {
                    let (row, col) = e.cursor_pos();
                    (row + 1, col + 1)
                })
            })
            .flatten();
        // Match count when the FIND drawer is the focused query context.
        let matches = (self.panels.focused() == PanelKind::Drawer
            && self.panels.active_drawer_view() == DrawerView::Find)
            .then(|| self.panels.query().result_count());
        let (global_hints, leader_timeout, gateway_label) = {
            let s = self.settings.read().unwrap();
            (
                crate::components::hints::global_hints(&s.key_bindings),
                std::time::Duration::from_millis(s.leader_timeout_ms),
                s.key_bindings
                    .first_combo_for(&ActionShortcuts::Leader)
                    .unwrap_or_else(|| "leader".to_string()),
            )
        };
        let ctx = crate::components::footer_bar::StatusContext {
            focus_label,
            editing,
            hints: &hints,
            global_hints: &global_hints,
            doc: crate::components::footer_bar::DocState {
                path: &path_str,
                dirty: self.panels.editor().is_some_and(|e| e.is_dirty()),
                ln_col,
                backlinks: self.doc_meta.backlinks(),
                git: self.doc_meta.git().cloned(),
                matches,
                link: link_segment,
                update: self
                    .update
                    .as_ref()
                    .map(|u| format!("⬆ {} available", u.latest)),
                rag: self.rag_status.label().map(|s| s.to_string()),
            },
        };
        self.footer.render(f, rows[2], theme, &ctx);

        // which-key overlay — docked above the status bar once the user
        // hesitates mid-sequence (spec §8b).
        let whichkey_visible = self
            .leader
            .pending_since()
            .is_some_and(|since| since.elapsed() >= leader_timeout);
        if whichkey_visible {
            let gateway = gateway_label;
            let area = f.area();
            let h = crate::components::which_key::desired_height(&self.leader, area.width)
                .min(rows[1].height);
            let rect =
                ratatui::layout::Rect::new(area.x, rows[2].y.saturating_sub(h), area.width, h);
            crate::components::which_key::render(f, rect, theme, &self.leader, &gateway);
        }

        // Overlay — rendered last so it appears on top of everything.
        self.overlays.render(f, f.area(), &self.theme);
    }

    async fn handle_app_message(&mut self, msg: AppEvent, tx: &AppTx) {
        match msg {
            // Overlay data belongs to the open overlay alone (see CONTEXT.md):
            // route it there and stop. `NotConsumed` — no overlay open, or not
            // the kind the data was addressed to — means the result is stale;
            // it is dropped here and nothing else ever sees it.
            AppEvent::OverlayData(data) => {
                self.overlays.handle_data(&data, &self.vault, tx);
            }
            AppEvent::Update(flow) => self.handle_update(flow, tx),
            AppEvent::FileOp(op) => self.handle_file_op(op, tx).await,
            AppEvent::SavedSearch(flow) => self.handle_saved_search(flow, tx),
            msg => {
                // Async status results (backlink count, git, link meta) are
                // DocMeta's; everything else reaches the owned match.
                let Some(msg) = self.doc_meta.handle(msg, &self.path) else {
                    return;
                };
                self.handle_owned_message(msg, tx).await;
            }
        }
    }

    /// The editor handles every path itself: notes open in the buffer,
    /// directories navigate the sidebar. Always consumes.
    async fn try_open_path(
        &mut self,
        path: VaultPath,
        emphasis: Option<Vec<String>>,
        tx: &AppTx,
    ) -> Option<VaultPath> {
        self.dismiss_overlay();
        if path.is_note() {
            self.open_path(path, emphasis, tx).await;
            self.focus_editor();
        } else {
            self.navigate_sidebar(path, tx);
        }
        None
    }

    async fn try_open_attachment(&mut self, path: VaultPath, tx: &AppTx) -> Option<VaultPath> {
        self.dismiss_overlay();
        self.open_attachment(path, tx).await;
        None
    }

    async fn on_exit(&mut self, _tx: &AppTx) {
        self.try_save().await;
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::keys::key_event_to_combo;

    /// Compile-time test: `PanelKind` and `OverlayKind` are usable here.
    #[test]
    fn panel_kind_labels_and_overlay_kind_compile() {
        assert_eq!(PanelKind::Editor.label(), "EDITOR");
        assert_eq!(PanelKind::Rail.label(), "RAIL");
        assert_eq!(DrawerView::Files.label(), "FILES");
        assert_eq!(DrawerView::Find.label(), "FIND");
        let _kind = OverlayKind::Dialog;
    }

    /// One screen over a fresh temp vault. Returns the `TempDir` so the vault
    /// directory outlives the test body.
    async fn test_screen() -> (
        EditorScreen,
        Arc<NoteVault>,
        SharedSettings,
        tempfile::TempDir,
    ) {
        use crate::settings::AppSettings;
        use kimun_core::VaultConfig;
        use std::sync::RwLock;

        let dir = tempfile::TempDir::new().unwrap();
        let vault = Arc::new(
            NoteVault::new(VaultConfig::new(crate::test_support::sys(dir.path())))
                .await
                .unwrap(),
        );
        let settings: SharedSettings = Arc::new(RwLock::new(AppSettings::default()));
        let screen = EditorScreen::new(vault.clone(), VaultPath::root(), settings.clone());
        (screen, vault, settings, dir)
    }

    fn key_event(code: ratatui::crossterm::event::KeyCode) -> InputEvent {
        use ratatui::crossterm::event::{KeyEvent, KeyModifiers};
        InputEvent::Key(KeyEvent::new(code, KeyModifiers::NONE))
    }

    fn ctrl_key(c: char) -> InputEvent {
        use ratatui::crossterm::event::{KeyCode, KeyEvent, KeyModifiers};
        InputEvent::Key(KeyEvent::new(KeyCode::Char(c), KeyModifiers::CONTROL))
    }

    fn chr(c: char) -> InputEvent {
        key_event(ratatui::crossterm::event::KeyCode::Char(c))
    }

    /// Ctrl-G (leader) then `o` `f` opens the FILES drawer — the full
    /// sequence fires with no menu drawn and no timeout wait.
    #[tokio::test]
    async fn leader_sequence_opens_drawer_view() {
        let (mut screen, _, _, _dir) = test_screen().await;
        let (tx, _rx) = tokio::sync::mpsc::unbounded_channel();

        // Start from a non-Files view so the switch is observable.
        screen.panels.open_drawer_view(DrawerView::Tags);

        screen.handle_input(&ctrl_key('g'), &tx);
        assert!(screen.leader.is_pending());
        screen.handle_input(&chr('o'), &tx);
        screen.handle_input(&chr('f'), &tx);

        assert!(!screen.leader.is_pending());
        assert_eq!(screen.panels.active_drawer_view(), DrawerView::Files);
        assert_eq!(screen.panels.focused(), PanelKind::Drawer);
    }

    /// Opening the FILES drawer points the sidebar at the current note's
    /// directory, not the stale dir it was last left on.
    #[tokio::test]
    async fn opening_files_drawer_reveals_current_note_dir() {
        let (mut screen, _, _, _dir) = test_screen().await;
        let (tx, _rx) = tokio::sync::mpsc::unbounded_channel();

        screen.path = VaultPath::new("projects").append(&VaultPath::note_path_from("plan"));
        // Sidebar left on an unrelated directory, drawer hidden.
        screen
            .panels
            .sidebar_mut()
            .navigate(VaultPath::new("other"), &tx);
        screen.panels.hide(PanelKind::Drawer);

        screen.open_drawer_view(DrawerView::Files, &tx);

        assert!(
            screen
                .panels
                .sidebar()
                .current_dir()
                .is_like(&VaultPath::new("projects"))
        );
    }

    /// With FILES already open but browsed elsewhere, the open-file-browser
    /// shortcut is the "where is my note" gesture: it re-reveals the current
    /// note's directory.
    #[tokio::test]
    async fn file_browser_shortcut_rereveals_note_dir_when_already_open() {
        let (mut screen, _, _, _dir) = test_screen().await;
        let (tx, _rx) = tokio::sync::mpsc::unbounded_channel();

        screen.path = VaultPath::new("projects").append(&VaultPath::note_path_from("plan"));
        screen.open_drawer_view(DrawerView::Files, &tx);
        // User browses away while FILES stays open.
        screen
            .panels
            .sidebar_mut()
            .navigate(VaultPath::new("other"), &tx);

        screen.handle_input(&ctrl_key('e'), &tx);

        assert!(
            screen
                .panels
                .sidebar()
                .current_dir()
                .is_like(&VaultPath::new("projects"))
        );
    }

    /// The gateway works mid-typing: with the editor focused, Ctrl-G arms
    /// the sequence and the next chars are consumed, not inserted.
    #[tokio::test]
    async fn leader_consumes_keys_while_editor_focused() {
        let (mut screen, _, _, _dir) = test_screen().await;
        let (tx, _rx) = tokio::sync::mpsc::unbounded_channel();

        screen.panels.editor_mut().unwrap().set_text(String::new());
        assert_eq!(screen.panels.focused(), PanelKind::Editor);

        screen.handle_input(&ctrl_key('g'), &tx);
        assert!(screen.leader.is_pending());
        // 'w' is a group key; it must not land in the buffer.
        screen.handle_input(&chr('w'), &tx);
        screen.handle_input(&chr('z'), &tx); // zen: hides the drawer
        assert_eq!(screen.panels.editor().unwrap().get_text(), "");
        assert!(!screen.panels.is_visible(PanelKind::Drawer));
    }

    /// Esc cancels a pending sequence and returns focus to the editor.
    #[tokio::test]
    async fn leader_esc_cancels_and_focuses_editor() {
        let (mut screen, _, _, _dir) = test_screen().await;
        let (tx, _rx) = tokio::sync::mpsc::unbounded_channel();

        screen.panels.focus(PanelKind::Rail);
        screen.handle_input(&ctrl_key('g'), &tx);
        screen.handle_input(&chr('f'), &tx);
        screen.handle_input(&key_event(ratatui::crossterm::event::KeyCode::Esc), &tx);

        assert!(!screen.leader.is_pending());
        assert_eq!(screen.panels.focused(), PanelKind::Editor);
    }

    /// Bare Space never leads — the leader is only the configured gateway.
    /// Space types a space in the editor and never arms the sequence, whatever
    /// panel is focused (rail, a list drawer, or a text-input drawer).
    #[tokio::test]
    async fn space_never_leads() {
        let (mut screen, _, _, _dir) = test_screen().await;
        let (tx, _rx) = tokio::sync::mpsc::unbounded_channel();

        // Editor focused: Space must insert a space.
        screen.panels.editor_mut().unwrap().set_text(String::new());
        screen.handle_input(&chr(' '), &tx);
        assert!(!screen.leader.is_pending());
        assert_eq!(screen.panels.editor().unwrap().get_text(), " ");

        // Rail focused: Space must NOT lead.
        screen.panels.focus(PanelKind::Rail);
        screen.handle_input(&chr(' '), &tx);
        assert!(!screen.leader.is_pending());

        // FIND drawer (a text input): Space must NOT lead.
        screen.panels.open_drawer_view(DrawerView::Find);
        screen.panels.focus(PanelKind::Drawer);
        screen.handle_input(&chr(' '), &tx);
        assert!(!screen.leader.is_pending());
    }

    #[tokio::test]
    async fn persist_saved_search_writes_via_core() {
        let (screen, _, _, _dir) = test_screen().await;

        screen.persist_saved_search("t", "#todo").await.unwrap();

        let all = screen.vault.list_saved_searches().await.unwrap();
        assert!(all.iter().any(|s| s.name == "t" && s.query == "#todo"));
    }

    #[tokio::test]
    async fn applying_saved_search_sets_panel_query_and_focuses_it() {
        let (mut screen, _, _, _dir) = test_screen().await;

        let (tx, _rx) = tokio::sync::mpsc::unbounded_channel();
        screen.apply_saved_search(
            "<{note}".to_string(),
            "Backlinks (current note)".to_string(),
            &tx,
        );
        assert!(screen.panels.is_visible(PanelKind::Drawer));
        assert_eq!(screen.panels.active_drawer_view(), DrawerView::Find);
        assert_eq!(screen.panels.query().active_query(), "<{note}");
        assert_eq!(screen.panels.focused(), PanelKind::Drawer);
    }

    #[tokio::test]
    async fn saved_search_persisted_repins_panel_breadcrumb() {
        let (mut screen, _, _, _dir) = test_screen().await;

        let (tx, _rx) = tokio::sync::mpsc::unbounded_channel();
        screen.apply_saved_search("#todo".to_string(), "todo".to_string(), &tx);
        screen
            .panels
            .query_mut()
            .set_active_query("#todo and #urgent".to_string());

        screen
            .handle_app_message(
                AppEvent::SavedSearch(SavedSearchFlow::Persisted {
                    name: "urgent-todos".to_string(),
                    query: "#todo and #urgent".to_string(),
                    source: SaveSource::QueryPanel,
                }),
                &tx,
            )
            .await;

        assert_eq!(
            screen.panels.query().saved_search_breadcrumb().as_deref(),
            Some("urgent-todos"),
            "a persisted panel-sourced save re-pins the breadcrumb"
        );
    }

    #[tokio::test]
    async fn persisted_note_browser_save_does_not_repin_even_on_equal_query() {
        let (mut screen, _, _, _dir) = test_screen().await;

        let (tx, _rx) = tokio::sync::mpsc::unbounded_channel();
        screen.apply_saved_search("#todo".to_string(), "todo".to_string(), &tx);

        // A note-browser-sourced save whose query text happens to equal the
        // panel's live query: source identity, not text equality, decides.
        screen
            .handle_app_message(
                AppEvent::SavedSearch(SavedSearchFlow::Persisted {
                    name: "inbox".to_string(),
                    query: "#todo".to_string(),
                    source: SaveSource::NoteBrowser,
                }),
                &tx,
            )
            .await;

        assert_eq!(
            screen.panels.query().saved_search_breadcrumb().as_deref(),
            Some("todo"),
            "a note-browser save must not steal the panel's provenance"
        );
    }

    #[tokio::test]
    async fn persisted_query_as_name_save_skips_repin() {
        let (mut screen, _, _, _dir) = test_screen().await;

        let (tx, _rx) = tokio::sync::mpsc::unbounded_channel();
        screen.apply_saved_search("#todo".to_string(), "todo".to_string(), &tx);

        // The empty-name fallback saved the query under its own text. Pinning
        // that as the breadcrumb name would just echo the query (CONTEXT.md:
        // the breadcrumb is a distinct provenance tag, not the query).
        screen
            .handle_app_message(
                AppEvent::SavedSearch(SavedSearchFlow::Persisted {
                    name: "#todo".to_string(),
                    query: "#todo".to_string(),
                    source: SaveSource::QueryPanel,
                }),
                &tx,
            )
            .await;

        assert_eq!(
            screen.panels.query().saved_search_breadcrumb().as_deref(),
            Some("todo"),
            "a query-as-name save leaves the breadcrumb alone"
        );
    }

    #[tokio::test]
    async fn save_search_confirmed_persists_then_emits_persisted() {
        let (mut screen, vault, _, _dir) = test_screen().await;

        let (tx, mut rx) = tokio::sync::mpsc::unbounded_channel();
        screen
            .handle_app_message(
                AppEvent::SavedSearch(SavedSearchFlow::Confirmed {
                    name: "mine".to_string(),
                    query: "#todo".to_string(),
                    source: SaveSource::QueryPanel,
                }),
                &tx,
            )
            .await;

        // The write runs in a spawned task; Persisted arrives only on success.
        let event = tokio::time::timeout(std::time::Duration::from_secs(5), async {
            loop {
                match rx.recv().await {
                    Some(e @ AppEvent::SavedSearch(SavedSearchFlow::Persisted { .. })) => break e,
                    Some(_) => continue,
                    None => panic!("channel closed before SavedSearchPersisted"),
                }
            }
        })
        .await
        .expect("SavedSearchPersisted within timeout");

        let AppEvent::SavedSearch(SavedSearchFlow::Persisted {
            name,
            query,
            source,
        }) = event
        else {
            unreachable!()
        };
        assert_eq!((name.as_str(), query.as_str()), ("mine", "#todo"));
        assert_eq!(source, SaveSource::QueryPanel);
        let all = vault.list_saved_searches().await.unwrap();
        assert!(all.iter().any(|s| s.name == "mine" && s.query == "#todo"));
    }

    #[tokio::test]
    async fn save_query_source_carries_panel_provenance() {
        let (mut screen, _, _, _dir) = test_screen().await;

        let (tx, _rx) = tokio::sync::mpsc::unbounded_channel();
        screen.apply_saved_search("#todo".to_string(), "todo".to_string(), &tx);

        assert_eq!(
            screen.save_query_source(),
            Some((
                "#todo".to_string(),
                Some("todo".to_string()),
                SaveSource::QueryPanel
            )),
            "the save dialog opens pre-filled with the breadcrumb provenance"
        );
    }

    // The try_save timeout-abort regression tests (commits 55eb49ed +
    // 5e28b796) previously lived here against `await_or_abort`. The
    // logic now lives in `SingleSlotTask::await_with_timeout` and is
    // covered by `single_slot_task_timeout_returns_none_keeps_handle`
    // in `crate::util::single_slot_task`.

    #[tokio::test]
    async fn saved_search_selected_then_close_overlay_keeps_backlinks_focus() {
        use crate::settings::AppSettings;
        use kimun_core::VaultConfig;
        use std::sync::RwLock;

        let dir = tempfile::TempDir::new().unwrap();
        let vault = Arc::new(
            NoteVault::new(VaultConfig::new(crate::test_support::sys(dir.path())))
                .await
                .unwrap(),
        );
        let settings: SharedSettings = Arc::new(RwLock::new(AppSettings::default()));
        let mut screen = EditorScreen::new(vault, VaultPath::root(), settings);

        let (tx, _rx) = tokio::sync::mpsc::unbounded_channel();
        // Replay the exact sequence the saved-searches modal emits on select.
        screen
            .handle_app_message(
                AppEvent::SavedSearch(SavedSearchFlow::Selected {
                    query: "<{note}".to_string(),
                    name: "Backlinks (current note)".to_string(),
                }),
                &tx,
            )
            .await;
        screen.handle_app_message(AppEvent::CloseOverlay, &tx).await;

        assert!(
            screen.panels.focused() == PanelKind::Drawer
                && screen.panels.active_drawer_view() == DrawerView::Find,
            "focus should remain on the FIND drawer after select + close"
        );
        assert!(!screen.overlays.is_open(), "overlay should be closed");
    }

    /// Capture-all guard: while an overlay is open, an opener action
    /// (QuickNote) must NOT replace it. Drives a real QuickNote keypress
    /// through `handle_input` so the guard in the action arm is exercised
    /// end-to-end.
    #[tokio::test]
    async fn opener_action_does_not_replace_open_overlay() {
        use crate::settings::AppSettings;
        use kimun_core::VaultConfig;
        use ratatui::crossterm::event::{KeyCode, KeyEvent, KeyModifiers};
        use std::sync::RwLock;

        let dir = tempfile::TempDir::new().unwrap();
        let vault = Arc::new(
            NoteVault::new(VaultConfig::new(crate::test_support::sys(dir.path())))
                .await
                .unwrap(),
        );
        let settings: SharedSettings = Arc::new(RwLock::new(AppSettings::default()));
        let mut screen = EditorScreen::new(vault.clone(), VaultPath::root(), settings.clone());

        let (tx, _rx) = tokio::sync::mpsc::unbounded_channel();

        // Force a SavedSearches overlay open and focus it, as if the user had
        // opened it via its action.
        {
            let s = settings.read().unwrap();
            let modal = SavedSearchesModal::new(
                vault.clone(),
                s.key_bindings.clone(),
                s.icons(),
                tx.clone(),
            );
            drop(s);
            screen.overlays.open(Box::new(modal), screen.opener_focus());
        }
        assert_eq!(
            screen.overlays.active_kind(),
            Some(OverlayKind::SavedSearches),
            "precondition: SavedSearches overlay is active"
        );

        // The QuickNote action key (Ctrl+W by default). Assert the binding
        // resolves to QuickNote so this test fails loudly if the default
        // rebinds, rather than silently exercising the wrong path.
        let quick_note_event = KeyEvent::new(KeyCode::Char('w'), KeyModifiers::CONTROL);
        {
            let s = settings.read().unwrap();
            let combo = key_event_to_combo(&quick_note_event).expect("Ctrl+W maps to a combo");
            assert_eq!(
                s.key_bindings.get_action(&combo),
                Some(ActionShortcuts::QuickNote),
                "test assumes Ctrl+W is bound to QuickNote"
            );
        }

        screen.handle_input(&InputEvent::Key(quick_note_event), &tx);

        // The guard must have suppressed the open: the SavedSearches overlay
        // is still active, NOT replaced by the QuickNote dialog.
        assert_eq!(
            screen.overlays.active_kind(),
            Some(OverlayKind::SavedSearches),
            "open overlay must not be replaced by a QuickNote opener action"
        );
    }

    /// Focus actions are inert while an overlay owns input: pressing
    /// FocusEditor (Ctrl+L) with a dialog open must not reveal or move the
    /// panels underneath, so closing the dialog leaves the layout unchanged.
    #[tokio::test]
    async fn focus_action_is_noop_while_overlay_open() {
        use crate::settings::AppSettings;
        use kimun_core::VaultConfig;
        use ratatui::crossterm::event::{KeyCode, KeyEvent, KeyModifiers};
        use std::sync::RwLock;

        let dir = tempfile::TempDir::new().unwrap();
        let vault = Arc::new(
            NoteVault::new(VaultConfig::new(crate::test_support::sys(dir.path())))
                .await
                .unwrap(),
        );
        let settings: SharedSettings = Arc::new(RwLock::new(AppSettings::default()));
        let mut screen = EditorScreen::new(vault.clone(), VaultPath::root(), settings.clone());

        let (tx, _rx) = tokio::sync::mpsc::unbounded_channel();

        // Open a SavedSearches overlay (Query panel starts hidden).
        {
            let s = settings.read().unwrap();
            let modal = SavedSearchesModal::new(
                vault.clone(),
                s.key_bindings.clone(),
                s.icons(),
                tx.clone(),
            );
            drop(s);
            screen.overlays.open(Box::new(modal), screen.opener_focus());
        }
        assert_ne!(screen.panels.active_drawer_view(), DrawerView::Find);
        let focused_before = screen.panels.focused();

        // Ctrl+L (FocusEditor / focus right) must be consumed but do nothing.
        let focus_right = KeyEvent::new(KeyCode::Char('l'), KeyModifiers::CONTROL);
        {
            let s = settings.read().unwrap();
            let combo = key_event_to_combo(&focus_right).expect("Ctrl+L maps to a combo");
            assert_eq!(
                s.key_bindings.get_action(&combo),
                Some(ActionShortcuts::FocusEditor),
                "test assumes Ctrl+L is bound to FocusEditor"
            );
        }
        screen.handle_input(&InputEvent::Key(focus_right), &tx);

        assert_eq!(
            screen.panels.focused(),
            focused_before,
            "focus action must not move focus while an overlay is open"
        );
        assert_ne!(
            screen.panels.active_drawer_view(),
            DrawerView::Find,
            "focus action must not switch the drawer view while an overlay is open"
        );
        assert_eq!(
            screen.overlays.active_kind(),
            Some(OverlayKind::SavedSearches),
            "overlay stays active"
        );
    }

    /// Opening the journal while an overlay is up dismisses the overlay, so the
    /// journal note isn't loaded behind it. OpenJournal is now resolved at the
    /// app level into an OpenPath, which lands here in `try_open_path` — that's
    /// the door that must dismiss the overlay.
    #[tokio::test(flavor = "multi_thread")]
    async fn open_journal_dismisses_open_overlay() {
        let vault = crate::test_support::temp_vault("editor-journal").await;
        vault.validate_and_init().await.unwrap();
        let settings = std::sync::Arc::new(std::sync::RwLock::new(
            crate::settings::AppSettings::default(),
        ));
        let mut screen = EditorScreen::new(vault.clone(), VaultPath::root(), settings.clone());
        let (tx, _rx) = tokio::sync::mpsc::unbounded_channel();

        {
            let s = settings.read().unwrap();
            let modal = SavedSearchesModal::new(
                vault.clone(),
                s.key_bindings.clone(),
                s.icons(),
                tx.clone(),
            );
            drop(s);
            screen.present_overlay(Box::new(modal));
        }
        assert!(screen.overlays.is_open(), "precondition: overlay open");

        let (details, _, _) = vault.journal_entry().await.unwrap();
        screen.try_open_path(details.path, None, &tx).await;

        assert!(
            !screen.overlays.is_open(),
            "opening the journal must dismiss the overlay before loading the note"
        );
    }

    /// Opening an attachment swaps the editor area to the read-only attachment
    /// view: the note editor accessor reports absent, and FollowLink in that
    /// state opens externally rather than touching the (absent) editor.
    #[tokio::test(flavor = "multi_thread")]
    async fn opening_attachment_shows_attachment_view() {
        let vault = crate::test_support::temp_vault("editor-attachment").await;
        vault.validate_and_init().await.unwrap();
        vault
            .save_attachment(&VaultPath::new("assets/diagram.png"), &[1, 2, 3])
            .await
            .unwrap();
        let settings = std::sync::Arc::new(std::sync::RwLock::new(
            crate::settings::AppSettings::default(),
        ));
        let mut screen = EditorScreen::new(vault.clone(), VaultPath::root(), settings);
        let (tx, _rx) = tokio::sync::mpsc::unbounded_channel();

        // Precondition: a note editor is mounted.
        assert!(screen.panels.editor().is_some());

        screen
            .try_open_attachment(VaultPath::new("assets/diagram.png"), &tx)
            .await;

        assert!(
            screen.panels.is_showing_attachment(),
            "the editor area shows the attachment view"
        );
        assert!(
            screen.panels.editor().is_none(),
            "no note editor is mounted while an attachment is shown"
        );
        assert_eq!(
            screen.panels.attachment_path(),
            Some(&VaultPath::new("assets/diagram.png"))
        );

        // Returning to a note swaps the editor area back.
        vault
            .create_note(&VaultPath::new("note.md"), "hi")
            .await
            .unwrap();
        screen.open_path(VaultPath::new("note.md"), None, &tx).await;
        assert!(!screen.panels.is_showing_attachment());
        assert!(screen.panels.editor().is_some());
    }

    #[tokio::test]
    async fn save_query_from_note_browser_opens_save_dialog() {
        use crate::settings::AppSettings;
        use kimun_core::VaultConfig;
        use ratatui::crossterm::event::{KeyCode, KeyEvent, KeyModifiers};
        use std::sync::RwLock;

        let dir = tempfile::TempDir::new().unwrap();
        let vault = Arc::new(
            NoteVault::new(VaultConfig::new(crate::test_support::sys(dir.path())))
                .await
                .unwrap(),
        );
        let settings: SharedSettings = Arc::new(RwLock::new(AppSettings::default()));
        let mut screen = EditorScreen::new(vault.clone(), VaultPath::root(), settings.clone());

        let (tx, _rx) = tokio::sync::mpsc::unbounded_channel();

        // Open a note browser carrying a query, as if the user typed "#todo".
        {
            let s = settings.read().unwrap();
            let provider = resolving_search_source(vault.clone(), s.current_last_paths(), None);
            let modal = NoteBrowserModal::with_initial_query(
                "Note Browser",
                BrowserScope::Query,
                provider,
                vault.clone(),
                s.key_bindings.clone(),
                s.icons(),
                tx.clone(),
                "#todo",
            );
            drop(s);
            screen.overlays.open(Box::new(modal), screen.opener_focus());
        }
        assert_eq!(
            screen.overlays.active_kind(),
            Some(OverlayKind::NoteBrowser),
            "precondition: note browser is active with a query"
        );
        assert_eq!(screen.overlays.active_query(), Some("#todo"));

        // Ctrl+D (SaveCurrentQuery) while the note browser is active should
        // replace it with the save-search dialog, sourcing the browser's query.
        let save_event = KeyEvent::new(KeyCode::Char('d'), KeyModifiers::CONTROL);
        {
            let s = settings.read().unwrap();
            let combo = key_event_to_combo(&save_event).expect("Ctrl+D maps to a combo");
            assert_eq!(
                s.key_bindings.get_action(&combo),
                Some(ActionShortcuts::SaveCurrentQuery),
                "test assumes Ctrl+D is bound to SaveCurrentQuery"
            );
        }

        screen.handle_input(&InputEvent::Key(save_event), &tx);

        assert_eq!(
            screen.overlays.active_kind(),
            Some(OverlayKind::Dialog),
            "saving from the note browser opens the save-search dialog"
        );
    }

    /// Renaming the open note keeps it open under the new path (retarget in
    /// place) instead of navigating away, and reloads the buffer clean.
    #[tokio::test(flavor = "multi_thread")]
    async fn renaming_open_note_retargets_in_place() {
        let vault = crate::test_support::temp_vault("editor-rename").await;
        vault.validate_and_init().await.unwrap();
        let from = VaultPath::note_path_from("old");
        vault.create_note(&from, "# Old\n\nbody").await.unwrap();
        let settings = std::sync::Arc::new(std::sync::RwLock::new(
            crate::settings::AppSettings::default(),
        ));
        let mut screen = EditorScreen::new(vault.clone(), from.clone(), settings);
        let (tx, _rx) = tokio::sync::mpsc::unbounded_channel();
        screen.on_enter(&tx).await;

        let to = VaultPath::note_path_from("new");
        vault.rename_note(&from, &to).await.unwrap();
        screen
            .handle_app_message(
                AppEvent::FileOp(FileOp::Renamed {
                    from: from.clone(),
                    to: to.clone(),
                }),
                &tx,
            )
            .await;

        assert_eq!(screen.path, to, "editor retargets to the new path");
        assert!(
            !screen.panels.editor().unwrap().is_dirty(),
            "reloaded buffer is clean (won't clobber the renamed file)"
        );
    }

    /// Opening a note marks its sidebar row; saving it (AutosaveCompleted with a
    /// new title) updates that row's title in place.
    #[tokio::test(flavor = "multi_thread")]
    async fn open_then_save_marks_and_retitles_sidebar_row() {
        let vault = crate::test_support::temp_vault("editor-marksave").await;
        vault.validate_and_init().await.unwrap();
        vault
            .create_note(&VaultPath::note_path_from("alpha"), "# Alpha\n\nbody")
            .await
            .unwrap();
        let settings = std::sync::Arc::new(std::sync::RwLock::new(
            crate::settings::AppSettings::default(),
        ));
        let path = VaultPath::note_path_from("alpha");
        let mut screen = EditorScreen::new(vault.clone(), path.clone(), settings);
        let (tx, _rx) = tokio::sync::mpsc::unbounded_channel();
        screen.on_enter(&tx).await;
        for _ in 0..50 {
            screen.panels.sidebar_mut().poll_for_test();
            if !screen.panels.sidebar().is_loading_for_test() {
                break;
            }
            tokio::time::sleep(std::time::Duration::from_millis(5)).await;
        }

        assert!(
            screen
                .panels
                .sidebar()
                .note_row_is_open_for_test("alpha.md"),
            "the open note's row is marked"
        );

        screen
            .handle_app_message(
                AppEvent::AutosaveCompleted {
                    path: path.clone(),
                    saved_revision: None,
                    title: Some("New First Line".to_string()),
                },
                &tx,
            )
            .await;

        assert_eq!(
            screen.panels.sidebar().note_row_title_for_test("alpha.md"),
            Some("New First Line".to_string()),
            "the saved note's row title updated in place"
        );
    }

    /// Switching the drawer view Ask → Files → Ask preserves the conversation:
    /// the resident thread panel is never dropped, so its turns are intact on
    /// the way back in (rules 1 & 2, CONTEXT.md: Thread lifetime).
    #[tokio::test]
    async fn ask_drawer_switch_preserves_thread() {
        let (mut screen, _, _, _dir) = test_screen().await;
        let (tx, _rx) = tokio::sync::mpsc::unbounded_channel();

        // Enter the Ask workspace and seed a couple of turns.
        screen.open_drawer_view(DrawerView::Ask, &tx);
        assert!(screen.panels.is_showing_ask());
        {
            let panel = screen.panels.ask_mut();
            panel.thread_mut().ask("first?".into());
            panel.thread_mut().ask("second?".into());
        }
        assert_eq!(screen.panels.ask().thread().turns().len(), 2);

        // Switch away: the editor area leaves Ask, but the resident thread
        // panel keeps the conversation.
        screen.open_drawer_view(DrawerView::Files, &tx);
        assert!(!screen.panels.is_showing_ask());
        assert_eq!(screen.panels.ask().thread().turns().len(), 2);

        // Switch back: the same conversation is on screen.
        screen.open_drawer_view(DrawerView::Ask, &tx);
        assert!(screen.panels.is_showing_ask());
        assert_eq!(
            screen.panels.ask().thread().turns().len(),
            2,
            "the conversation survives the round trip"
        );
    }

    /// An `AskData::AnswerReady` delivered through the screen's real message
    /// pump (`handle_app_message`, the same entry point the app loop uses —
    /// not the coordinator's `handle_data` called directly) must still land on
    /// the thread: it should route through `handle_owned_message`'s
    /// `AppEvent::Ask(data)` arm to `AskCoordinator::handle_data` end to end.
    #[tokio::test]
    async fn ask_answer_ready_reaches_the_thread_via_the_owned_message_path() {
        let (mut screen, _, _, _dir) = test_screen().await;
        let (tx, _rx) = tokio::sync::mpsc::unbounded_channel();

        screen.open_drawer_view(DrawerView::Ask, &tx);
        let id = screen.panels.ask_mut().thread_mut().ask("q?".into());

        screen
            .handle_app_message(
                AppEvent::Ask(crate::components::events::AskData::AnswerReady {
                    turn_id: id,
                    result: Ok(("the answer".into(), vec![])),
                }),
                &tx,
            )
            .await;

        let panel = screen.panels.ask_mut();
        let turn = panel.thread().selected().expect("a turn is selected");
        assert!(matches!(turn.status, crate::ask::TurnStatus::Done));
        assert_eq!(turn.answer, "the answer");
    }

    /// Opening a note from the browser while the Ask workspace is shown must
    /// swap the editor area to the note (carry-forward: `open_path` calls
    /// `clear_attachment`, which no-ops on Ask, so the stash is the only thing
    /// that gets the note on screen) — and the thread survives to be re-shown.
    #[tokio::test]
    async fn opening_a_note_over_ask_shows_the_note_and_keeps_the_thread() {
        let vault = crate::test_support::temp_vault("editor-ask-open").await;
        vault.validate_and_init().await.unwrap();
        vault
            .create_note(&VaultPath::note_path_from("alpha"), "# Alpha\n\nbody")
            .await
            .unwrap();
        let settings = std::sync::Arc::new(std::sync::RwLock::new(
            crate::settings::AppSettings::default(),
        ));
        let mut screen = EditorScreen::new(vault, VaultPath::root(), settings);
        let (tx, _rx) = tokio::sync::mpsc::unbounded_channel();

        screen.open_drawer_view(DrawerView::Ask, &tx);
        screen
            .panels
            .ask_mut()
            .thread_mut()
            .ask("a question?".into());
        assert!(screen.panels.is_showing_ask());

        // Open a note: the editor area must show it, not the thread.
        screen
            .open_path(VaultPath::note_path_from("alpha"), None, &tx)
            .await;
        assert!(!screen.panels.is_showing_ask(), "the note replaced Ask");
        assert!(screen.panels.editor().is_some(), "the note editor is shown");
        assert_eq!(
            screen.panels.active_drawer_view(),
            DrawerView::Files,
            "the Sources drawer must not linger on a hidden conversation"
        );

        // Re-enter Ask: the resident conversation comes back intact.
        screen.open_drawer_view(DrawerView::Ask, &tx);
        assert_eq!(
            screen.panels.ask().thread().turns().len(),
            1,
            "the thread survived opening the note"
        );
    }

    /// Opening a note while Ask is shown but the drawer was explicitly hidden
    /// must switch the drawer's view to FILES *without* re-revealing it — the
    /// view switch preserves visibility (fold-in #4). Before the fix the
    /// FILES switch went through `open_drawer_view`, which force-showed a
    /// drawer the user had hidden.
    #[tokio::test]
    async fn opening_a_note_over_ask_with_hidden_drawer_keeps_it_hidden() {
        let vault = crate::test_support::temp_vault("editor-ask-hidden-drawer").await;
        vault.validate_and_init().await.unwrap();
        vault
            .create_note(&VaultPath::note_path_from("alpha"), "# Alpha\n\nbody")
            .await
            .unwrap();
        let settings = std::sync::Arc::new(std::sync::RwLock::new(
            crate::settings::AppSettings::default(),
        ));
        let mut screen = EditorScreen::new(vault, VaultPath::root(), settings);
        let (tx, _rx) = tokio::sync::mpsc::unbounded_channel();

        // Enter Ask, then hide the drawer while the workspace stays on screen.
        screen.open_drawer_view(DrawerView::Ask, &tx);
        screen.panels.hide(PanelKind::Drawer);
        assert!(!screen.panels.is_visible(PanelKind::Drawer));
        assert!(screen.panels.is_showing_ask());

        // Open a note: Ask leaves the editor area and the drawer view switches
        // to FILES, but the drawer must stay hidden.
        screen
            .open_path(VaultPath::note_path_from("alpha"), None, &tx)
            .await;
        assert!(!screen.panels.is_showing_ask(), "the note replaced Ask");
        assert!(
            !screen.panels.is_visible(PanelKind::Drawer),
            "a hidden drawer must not be force-revealed"
        );
        assert_eq!(
            screen.panels.active_drawer_view(),
            DrawerView::Files,
            "the view switched off Ask to FILES"
        );
    }

    /// Regression for the rail-click toggle bug: before the fix, opening a
    /// note over Ask left the drawer's active view stuck on `Ask` (only the
    /// editor-area content moved), so the next `OpenDrawerView(Ask)` — what a
    /// rail click sends — read as "already showing, toggle it closed"
    /// instead of "reopen it", requiring a second click. Drives the real
    /// `AppEvent::OpenDrawerView` path (not the direct `open_drawer_view`
    /// helper) so this test actually exercises that toggle branch.
    #[tokio::test]
    async fn rail_click_reenters_ask_in_one_click_after_a_note_stashed_it() {
        let vault = crate::test_support::temp_vault("editor-ask-rail-reentry").await;
        vault.validate_and_init().await.unwrap();
        vault
            .create_note(&VaultPath::note_path_from("alpha"), "# Alpha\n\nbody")
            .await
            .unwrap();
        let settings = std::sync::Arc::new(std::sync::RwLock::new(
            crate::settings::AppSettings::default(),
        ));
        let mut screen = EditorScreen::new(vault, VaultPath::root(), settings);
        screen.rag_status = crate::rag::RagStatus::Online {
            llm_available: true,
        };
        let (tx, _rx) = tokio::sync::mpsc::unbounded_channel();

        screen
            .handle_app_message(AppEvent::OpenDrawerView(DrawerView::Ask), &tx)
            .await;
        assert!(screen.panels.is_showing_ask());
        screen
            .panels
            .ask_mut()
            .thread_mut()
            .ask("a question?".into());

        screen
            .open_path(VaultPath::note_path_from("alpha"), None, &tx)
            .await;
        assert!(!screen.panels.is_showing_ask());

        // One click — one `OpenDrawerView(Ask)` — must land back on Ask.
        screen
            .handle_app_message(AppEvent::OpenDrawerView(DrawerView::Ask), &tx)
            .await;
        assert!(
            screen.panels.is_showing_ask(),
            "a single reopen must not read as a toggle-off"
        );
        assert_eq!(
            screen.panels.ask().thread().turns().len(),
            1,
            "the thread survived the round trip"
        );
    }

    /// Opening an attachment while the Ask workspace is shown must swap the
    /// editor area to the attachment view (`show_attachment` leaves Ask content
    /// alone, so the stash is the only thing that gets it off screen) — and the
    /// thread survives to be re-shown. Mirrors the open-note-over-Ask case for
    /// the attachment entry point.
    #[tokio::test]
    async fn opening_an_attachment_over_ask_shows_it_and_keeps_the_thread() {
        let vault = crate::test_support::temp_vault("editor-ask-open-att").await;
        vault.validate_and_init().await.unwrap();
        let att_path = VaultPath::new("pic.png");
        vault
            .save_attachment(&att_path, b"\x89PNG\r\n\x1a\n")
            .await
            .unwrap();
        let settings = std::sync::Arc::new(std::sync::RwLock::new(
            crate::settings::AppSettings::default(),
        ));
        let mut screen = EditorScreen::new(vault, VaultPath::root(), settings);
        let (tx, _rx) = tokio::sync::mpsc::unbounded_channel();

        screen.open_drawer_view(DrawerView::Ask, &tx);
        screen
            .panels
            .ask_mut()
            .thread_mut()
            .ask("a question?".into());
        assert!(screen.panels.is_showing_ask());

        // Open an attachment: the editor area must show it, not the thread.
        screen.open_attachment(att_path, &tx).await;
        assert!(
            !screen.panels.is_showing_ask(),
            "the attachment replaced Ask"
        );

        // Re-enter Ask: the stashed conversation comes back intact.
        screen.open_drawer_view(DrawerView::Ask, &tx);
        assert_eq!(
            screen.panels.ask().thread().turns().len(),
            1,
            "the thread survived opening the attachment"
        );
    }

    /// Client presence at the screen seam: with no LLM-capable server there is
    /// no client, so the resident Ask panel's composer is disabled (never a
    /// forever-`Thinking` turn; carry-forward #2).
    #[tokio::test]
    async fn refresh_ask_capability_disables_without_a_client() {
        let (mut screen, _, _, _dir) = test_screen().await;

        // rag_status is Disabled here → no client → composer disabled.
        screen
            .ask
            .refresh_capability(&mut screen.panels, screen.rag_status)
            .await;
        assert!(
            !screen.panels.ask().has_client(),
            "the resident Ask panel loses its client without an LLM server"
        );
    }

    /// An answer that lands while the user is browsing FILES (Ask not shown) is
    /// delivered to the resident thread, not dropped (rule 3).
    #[tokio::test]
    async fn answer_lands_on_the_thread_while_browsing_files() {
        let (mut screen, _, _, _dir) = test_screen().await;
        let (tx, _rx) = tokio::sync::mpsc::unbounded_channel();

        screen.open_drawer_view(DrawerView::Ask, &tx);
        let turn_id = screen.panels.ask_mut().thread_mut().ask("q?".into());
        // Leave Ask: the in-flight turn stays on the resident panel.
        screen.open_drawer_view(DrawerView::Files, &tx);
        assert!(!screen.panels.is_showing_ask());

        screen.ask.handle_data(
            &mut screen.panels,
            crate::components::events::AskData::AnswerReady {
                turn_id,
                result: Ok(("the answer".into(), vec![])),
            },
            &tx,
        );

        let thread = screen.panels.ask().thread();
        let turn = thread.turns().iter().find(|t| t.id == turn_id).unwrap();
        assert!(
            matches!(turn.status, crate::ask::TurnStatus::Done),
            "the answer completed the turn"
        );
    }

    /// SEM's rail entry is live-status-driven, exactly like ASK: hidden until a
    /// health probe reports the server reachable for search, shown for a
    /// semantic-only server (search works, ASK stays hidden), and hidden again
    /// when the server drops offline.
    #[tokio::test]
    async fn sem_rail_entry_tracks_search_availability() {
        let (mut screen, _, _, _dir) = test_screen().await;
        let (tx, _rx) = tokio::sync::mpsc::unbounded_channel();

        // Startup: no status yet → SEM (and ASK) hidden.
        assert!(!screen.panels.rail_shows(DrawerView::Semantic));
        assert!(!screen.panels.rail_shows(DrawerView::Ask));

        // Semantic-only server comes online: SEM appears, ASK stays hidden.
        screen
            .handle_owned_message(
                AppEvent::RagStatus(crate::rag::RagStatus::Online {
                    llm_available: false,
                }),
                &tx,
            )
            .await;
        assert!(screen.panels.rail_shows(DrawerView::Semantic));
        assert!(!screen.panels.rail_shows(DrawerView::Ask));

        // Server drops offline: SEM disappears too (not driven by config).
        screen
            .handle_owned_message(AppEvent::RagStatus(crate::rag::RagStatus::Offline), &tx)
            .await;
        assert!(!screen.panels.rail_shows(DrawerView::Semantic));

        // LLM-capable server: both SEM and ASK appear.
        screen
            .handle_owned_message(
                AppEvent::RagStatus(crate::rag::RagStatus::Online {
                    llm_available: true,
                }),
                &tx,
            )
            .await;
        assert!(screen.panels.rail_shows(DrawerView::Semantic));
        assert!(screen.panels.rail_shows(DrawerView::Ask));
    }

    /// Leader `a a` (`open_ask_workspace`) gates on `llm_available` only for
    /// the enter-from-outside path. Once Ask is already showing, the
    /// sibling `a n`/`a y`/`a e`/`a r` actions all work on a degraded
    /// (capability-off) thread, so re-focusing the composer must be
    /// consistent with them rather than flashing the gate message again.
    #[tokio::test]
    async fn ask_focus_skips_the_llm_gate_when_already_showing_ask() {
        let (mut screen, _, _, _dir) = test_screen().await;
        let (tx, mut rx) = tokio::sync::mpsc::unbounded_channel();

        screen.rag_status = crate::rag::RagStatus::Online {
            llm_available: true,
        };
        screen.open_ask_workspace(&tx);
        assert!(screen.panels.is_showing_ask());

        // Capability drops mid-conversation: the thread stays on screen with
        // the composer merely disabled, never evicted.
        screen.rag_status = crate::rag::RagStatus::Offline;

        screen.open_ask_workspace(&tx);
        assert!(screen.panels.is_showing_ask(), "still showing Ask");
        assert_eq!(screen.panels.focused(), PanelKind::Editor);
        assert!(
            rx.try_recv().is_err(),
            "no gate flash while Ask is already showing"
        );
    }

    // ── Following a link with the mouse: the screen's half of the rule ──────
    //
    // `ClickRun` owns which *mouse* events are one gesture and is tested
    // against a real event sequence there. What `track_click` owns is
    // everything the run cannot answer for itself — is this a mouse event, is
    // an overlay in the way, did the press land on the note buffer — and that
    // last one is a hit-test, which is where the frame-counted-as-buffer defect
    // lived.

    /// Lay the screen out by rendering it, so the hit-test reads the rects a
    /// real frame produced rather than defaults.
    fn lay_out(screen: &mut EditorScreen) {
        let mut term = ratatui::Terminal::new(ratatui::backend::TestBackend::new(120, 40)).unwrap();
        term.draw(|f| screen.render(f)).unwrap();
    }

    /// The buffer's top-left cell, found by asking the screen's own gate — so
    /// the coordinates cannot drift from the layout the way a literal would.
    fn buffer_origin(screen: &EditorScreen) -> (u16, u16) {
        (0..40u16)
            .flat_map(|row| (0..120u16).map(move |col| (col, row)))
            .find(|(col, row)| screen.panels.is_note_buffer_cell(*col, *row))
            .expect("a laid-out screen always shows the note buffer")
    }

    /// A cell on the frame `PanelSet::render` draws around the editor: the
    /// corner one row above and one column left of the buffer's first cell.
    ///
    /// The assert is the point, not a formality. Deriving the probe from
    /// [`buffer_origin`] means the gate picks where the test looks, so a gate
    /// that answered "the editor column" would slide this probe out of the
    /// column with it and every frame assertion below would hold vacuously.
    /// Focus is the independent witness: `PanelSet::handle_mouse` focuses the
    /// panel whose *column* contains the press, and it is the column, not the
    /// buffer, that this cell has to be inside for the tests to mean anything.
    fn frame_corner(screen: &mut EditorScreen, tx: &AppTx) -> (u16, u16) {
        let (col, row) = buffer_origin(screen);
        let corner = (col - 1, row - 1);
        screen.panels.focus(PanelKind::Drawer);
        screen.handle_input(&press_at(corner.0, corner.1), tx);
        assert_eq!(
            screen.panels.focused(),
            PanelKind::Editor,
            "precondition: the frame is inside the editor column"
        );
        // That probe was a real press. Drop it so the run starts clean.
        screen.clicks.end();
        corner
    }

    fn press_at(col: u16, row: u16) -> InputEvent {
        use ratatui::crossterm::event::{KeyModifiers, MouseButton, MouseEvent, MouseEventKind};
        InputEvent::Mouse(MouseEvent {
            kind: MouseEventKind::Down(MouseButton::Left),
            column: col,
            row,
            modifiers: KeyModifiers::NONE,
        })
    }

    fn moved_at(col: u16, row: u16) -> InputEvent {
        use ratatui::crossterm::event::{KeyModifiers, MouseEvent, MouseEventKind};
        InputEvent::Mouse(MouseEvent {
            kind: MouseEventKind::Moved,
            column: col,
            row,
            modifiers: KeyModifiers::NONE,
        })
    }

    /// A fixed origin, so the tests describe gaps rather than wall-clock time.
    fn at(millis: u64) -> std::time::Instant {
        static ORIGIN: std::sync::OnceLock<std::time::Instant> = std::sync::OnceLock::new();
        *ORIGIN.get_or_init(std::time::Instant::now) + std::time::Duration::from_millis(millis)
    }

    #[tokio::test]
    async fn two_presses_on_the_buffer_are_a_double_click() {
        let (mut screen, _, _, _dir) = test_screen().await;
        lay_out(&mut screen);
        let (col, row) = buffer_origin(&screen);

        assert!(!screen.track_click(&press_at(col, row), at(0)));
        assert!(screen.track_click(&press_at(col, row), at(120)));
    }

    /// The gate is not the editor *column*: `PanelSet::render` frames the
    /// component, and a press on that frame never reaches the component's
    /// `handle_mouse`, so the cursor stays where it was. Counting those cells
    /// let two clicks on the `─ Editor` title bar follow whichever link the
    /// cursor was parked on — a note the user never pointed at.
    #[tokio::test]
    async fn a_press_on_the_editor_frame_is_never_half_of_a_double() {
        let (mut screen, _, _, _dir) = test_screen().await;
        let (tx, _rx) = tokio::sync::mpsc::unbounded_channel();
        lay_out(&mut screen);
        let (col, row) = frame_corner(&mut screen, &tx);

        assert!(!screen.track_click(&press_at(col, row), at(0)));
        assert!(
            !screen.track_click(&press_at(col, row), at(120)),
            "two clicks on the frame are not a follow"
        );
    }

    /// A frame press does not merely fail to pair — it ends the run, so it
    /// cannot sit unnoticed between two buffer presses and let them pair
    /// across it.
    #[tokio::test]
    async fn a_frame_press_separates_two_buffer_presses() {
        let (mut screen, _, _, _dir) = test_screen().await;
        let (tx, _rx) = tokio::sync::mpsc::unbounded_channel();
        lay_out(&mut screen);
        let (frame_col, frame_row) = frame_corner(&mut screen, &tx);
        let (col, row) = buffer_origin(&screen);

        screen.track_click(&press_at(col, row), at(0));
        screen.track_click(&press_at(frame_col, frame_row), at(40));
        assert!(!screen.track_click(&press_at(col, row), at(80)));
    }

    /// Only a press consults the hit-test. Any-event tracking delivers a
    /// `Moved` per cell of travel, including over the frame, and the pointer
    /// crossing the border mid-gesture is not the user doing anything.
    #[tokio::test]
    async fn motion_over_the_frame_does_not_break_a_double() {
        let (mut screen, _, _, _dir) = test_screen().await;
        let (tx, _rx) = tokio::sync::mpsc::unbounded_channel();
        lay_out(&mut screen);
        let (frame_col, frame_row) = frame_corner(&mut screen, &tx);
        let (col, row) = buffer_origin(&screen);

        screen.track_click(&press_at(col, row), at(0));
        assert!(!screen.track_click(&moved_at(frame_col, frame_row), at(40)));
        assert!(screen.track_click(&press_at(col, row), at(120)));
    }

    #[tokio::test]
    async fn a_key_between_presses_ends_the_click_run() {
        let (mut screen, _, _, _dir) = test_screen().await;
        lay_out(&mut screen);
        let (col, row) = buffer_origin(&screen);

        screen.track_click(&press_at(col, row), at(0));
        assert!(!screen.track_click(&chr('x'), at(40)));
        assert!(!screen.track_click(&press_at(col, row), at(80)));
    }

    /// An overlay ends the run rather than merely failing to extend it. A modal
    /// is drawn over the editor column and a `SearchList` activates a row on a
    /// click-click of its own; without ending it, those presses stay in the run
    /// and pair with the first one that lands after the overlay closes.
    #[tokio::test]
    async fn an_overlay_ends_the_click_run() {
        let (mut screen, _, _, _dir) = test_screen().await;
        lay_out(&mut screen);
        let (col, row) = buffer_origin(&screen);
        let vault = screen.vault.clone();

        screen.track_click(&press_at(col, row), at(0));
        screen.present_overlay(Box::new(ActiveDialog::create_note(
            VaultPath::note_path_from("x"),
            vault,
            None,
        )));
        assert!(
            !screen.track_click(&press_at(col, row), at(40)),
            "a press under an overlay is the overlay's"
        );
        screen.dismiss_overlay();
        assert!(
            !screen.track_click(&press_at(col, row), at(80)),
            "and neither press survives to pair with the next one"
        );
    }

    /// End to end: the second press of a pair over a wikilink emits the same
    /// `FollowLink` the bound shortcut does. The first press is what placed the
    /// cursor the second one asks about, which is why one path serves both.
    #[tokio::test]
    async fn a_double_click_on_a_wikilink_follows_it() {
        let (mut screen, _, _, _dir) = test_screen().await;
        let (tx, mut rx) = tokio::sync::mpsc::unbounded_channel();
        screen
            .panels
            .editor_mut()
            .unwrap()
            .set_text("[[target note]]".to_string());
        lay_out(&mut screen);
        // Mid-link, so the exact gutter width the editor renders cannot move
        // the press off the span.
        let (col, row) = buffer_origin(&screen);
        let (col, row) = (col + 6, row);

        screen.handle_input(&press_at(col, row), &tx);
        screen.handle_input(&press_at(col, row), &tx);

        let followed = std::iter::from_fn(|| rx.try_recv().ok())
            .find_map(|ev| match ev {
                AppEvent::FollowLink(target) => Some(target),
                _ => None,
            })
            .expect("the double-click emitted no FollowLink");
        assert_eq!(followed, "target note");
    }

    /// The first press only places the cursor. Following on a single click is
    /// the behaviour this replaced: a stray click while reading would navigate.
    #[tokio::test]
    async fn a_single_press_on_a_wikilink_only_places_the_cursor() {
        let (mut screen, _, _, _dir) = test_screen().await;
        let (tx, mut rx) = tokio::sync::mpsc::unbounded_channel();
        screen
            .panels
            .editor_mut()
            .unwrap()
            .set_text("[[target note]]".to_string());
        lay_out(&mut screen);
        let (col, row) = buffer_origin(&screen);

        screen.handle_input(&press_at(col + 6, row), &tx);

        assert!(
            !std::iter::from_fn(|| rx.try_recv().ok())
                .any(|ev| matches!(ev, AppEvent::FollowLink(_))),
            "one click is a cursor placement, not a navigation"
        );
        assert!(
            screen
                .panels
                .editor()
                .unwrap()
                .follow_target_at_cursor()
                .is_some(),
            "but it did land on the link, so the next press has something to follow"
        );
    }
}

#[cfg(test)]
mod sort_routing_tests {
    use super::*;
    use crate::app_screen::AppScreen;
    use crate::components::events::SortTarget;
    use crate::components::file_list::{SortField, SortOrder};

    async fn make_editor() -> (
        EditorScreen,
        AppTx,
        tokio::sync::mpsc::UnboundedReceiver<AppEvent>,
    ) {
        let vault = crate::test_support::temp_vault("editor-sort").await;
        vault.validate_and_init().await.unwrap();
        let settings = std::sync::Arc::new(std::sync::RwLock::new(
            crate::settings::AppSettings::default(),
        ));
        let screen = EditorScreen::new(vault, VaultPath::root(), settings);
        let (tx, rx) = tokio::sync::mpsc::unbounded_channel();
        (screen, tx, rx)
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn sort_save_default_persists_to_settings() {
        let (mut screen, tx, _rx) = make_editor().await;
        screen
            .handle_app_message(
                AppEvent::SortChanged {
                    target: SortTarget::Sidebar,
                    field: SortField::Title,
                    order: SortOrder::Descending,
                    group_directories: true,
                    persist: true,
                },
                &tx,
            )
            .await;
        let s = screen.settings.read().unwrap();
        assert_eq!(
            s.default_sort_field,
            crate::settings::SortFieldSetting::Title
        );
        assert_eq!(
            s.default_sort_order,
            crate::settings::SortOrderSetting::Descending
        );
        assert!(s.group_directories);
    }

    #[tokio::test(flavor = "multi_thread")]
    async fn sort_save_default_journal_dir_writes_journal_settings() {
        let (mut screen, tx, _rx) = make_editor().await;
        // Point the sidebar at the journal directory (current_dir set synchronously).
        let journal = screen.vault.journal_path().clone();
        screen.panels.sidebar_mut().navigate(journal, &tx);

        screen
            .handle_app_message(
                AppEvent::SortChanged {
                    target: SortTarget::Sidebar,
                    field: SortField::Title,
                    order: SortOrder::Ascending,
                    group_directories: false,
                    persist: true,
                },
                &tx,
            )
            .await;

        let s = screen.settings.read().unwrap();
        assert_eq!(
            s.journal_sort_field,
            crate::settings::SortFieldSetting::Title
        );
        assert_eq!(
            s.journal_sort_order,
            crate::settings::SortOrderSetting::Ascending
        );
        // Default (non-journal) settings must be untouched from their defaults.
        assert_eq!(
            s.default_sort_field,
            crate::settings::SortFieldSetting::Name
        );
    }

    /// A non-persisting SortChanged (a plain dialog toggle) applies live but
    /// must NOT write settings.
    #[tokio::test(flavor = "multi_thread")]
    async fn sort_changed_without_persist_leaves_settings() {
        let (mut screen, tx, _rx) = make_editor().await;
        screen
            .handle_app_message(
                AppEvent::SortChanged {
                    target: SortTarget::Sidebar,
                    field: SortField::Title,
                    order: SortOrder::Descending,
                    group_directories: true,
                    persist: false,
                },
                &tx,
            )
            .await;
        let s = screen.settings.read().unwrap();
        assert_eq!(
            s.default_sort_field,
            crate::settings::SortFieldSetting::Name
        );
        assert_eq!(
            s.default_sort_order,
            crate::settings::SortOrderSetting::Ascending
        );
        assert!(!s.group_directories);
    }
}