Struct Workbench 

pub struct Workbench {
    pub id: &'static str,
    pub label: &'static str,
    pub glyph: &'static str,
    pub includes: fn(&FeatureInfo<'_>) -> bool,
    pub buttons: &'static [WorkbenchButton],
    pub panels: &'static [&'static str],
}

One workbench: a UI filter + optional toolbar buttons + claimed panels. Fully 'static — fn-pointer predicate and &'static slices, no OnceLock.

Fields

id: &'static str

Stable id, e.g. "all" / "modeling" / "sheetMetal" — the value stored in RenderSettings.workbench and published to the verifier.

label: &'static str

Human label for the dropdown, e.g. "Sheet Metal".

glyph: &'static str

SVG catalog key used by the workbench switcher.

includes: fn(&FeatureInfo<'_>) -> bool

This workbench OWNS its inclusion decision: does a catalogue entry belong in this workbench’s feature-creation UI?

buttons: &'static [WorkbenchButton]

Extra toolbar buttons this workbench adds (data only). EMPTY in v1.

panels: &'static [&'static str]

Ids of EXISTING panels this workbench CLAIMS. Claim-based, not hide-based: a panel is visible unless it is claimed by ≥1 workbench and the active one does not list it (see panel_visible). EMPTY in v1 (nothing claimed → every panel visible everywhere). Phase 2 adds claims here, editing NO other file — the same anti-rot property the button union gives.