AI-suggested commit message & description (claude -p primary)

[Sph3ricalPeter]

Goal

Generate a suggested commit message + description from the staged diff using the shared AI substrate (#57) — primarily the user's claude -p (BYO Claude Code), with Local (Ollama) / BYOK as fallback tiers. Entry point: a button in the commit box (src/components/staging/commit-box.tsx).

Decision (2026-06-20)

• Uses the same substrate + config as [feat] Tiered AI configuration — Claude Code (claude -p) as primary substrate #57 — Claude Code (claude -p) first, Local / BYOK fallback. No separate model path. (Resolves the old "which local runtime?" open question — decided in [feat] Tiered AI configuration — Claude Code (claude -p) as primary substrate #57.)
• Part of the AI layer = last stage of the v2.0.0 pivot; quiet polish on top of the no-AI spine. Off by default.

Scope

• Single bounded claude -p --output-format json call over the staged diff (respecting the configured tier); returns subject + body suggestion.
• Pre-fills the commit box as an editable suggestion — never auto-commits.
• Degrades gracefully when the substrate is unavailable.

Relationship to other issues

• Shares runtime/config with [feat] Tiered AI configuration — Claude Code (claude -p) as primary substrate #57 (substrate) and [feat] Risk-flagging review pane — AI layer (claude -p primary) #53 (review pane) — one AI path, not three.