nils-term 0.6.0

# nils-term

## Overview

Small terminal utilities shared across the workspace.

## Shared helper policy

### What belongs in `nils-term`

- Domain-neutral progress primitives that can be reused by multiple binaries.
- Structured APIs (`Progress`, `ProgressOptions`, `ProgressEnabled`) that callers can compose.
- Behavior that can be verified with deterministic unit/integration tests.

### What stays crate-local

- Product-specific progress copy, emoji/prefix style, and section wording.
- CLI-specific policy decisions about when progress should appear for a command.
- Exit-code mapping and command-level error/warning text.

## Progress

`nils-term` provides a minimal, RAII-friendly progress abstraction that is safe for
machine-readable stdout output:

- progress is drawn to **stderr** by default
- with `ProgressEnabled::Auto` (default), progress is enabled only when **stderr is a TTY**

### Determinate progress

```rust
use nils_term::progress::{Progress, ProgressOptions};

let total = 3_u64;
let progress = Progress::new(total, ProgressOptions::default().with_prefix("work "));

for i in 0..total {
    progress.set_message(format!("item {i}"));
    progress.inc(1);
}

progress.finish();
```

### Spinner progress

```rust
use nils_term::progress::{Progress, ProgressFinish, ProgressOptions};

let spinner = Progress::spinner(
    ProgressOptions::default()
        .with_prefix("fetch ")
        .with_finish(ProgressFinish::Clear),
);

spinner.set_message("loading");
spinner.tick();
spinner.finish_and_clear();
```

### Library guidance

Prefer accepting a `Progress` (or `ProgressOptions`) from the caller instead of reading env vars
inside library code. This keeps libraries deterministic and lets binaries decide whether to show
progress (e.g. interactive vs CI).

## Migration guidance

When migrating crate-local progress code into `nils-term`:

1. Add/keep characterization tests before moving behavior.
2. Keep progress rendering to `stderr` so machine-readable `stdout` remains stable.
3. Keep CLI-local adapters for command wording and error/exit semantics.
4. Re-run command-contract tests for TTY, non-TTY, JSON, and `NO_COLOR` flows.

## Docs

- [Docs index](docs/README.md)