Beagle SCM

COMMIT-001: commit: projection should surface the diff after the metadata

be commit:?<sha> (keeper projector, see Projector) emits only the commit object body — headers then message — so it shows who/when/why but never what changed. git show folds the diff in; beagle keeps them split, forcing a second be diff:?<sha>. This ticket surfaces the diff from commit:.

Input

Context

• commit: is keeper-owned and emits headers + message only; diff: is a separate graf-owned projector. There is no single "show this commit" view.

Goals

• After the commit metadata, surface the commit's diff so commit: reads like git show.
• Preferred: emit a navigable link to diff:?<sha> (graf's projector) that Bro can follow — keeps commit: single-purpose, reuses graf's diff renderer, no diff code in keeper.
• Alternative: inline graf's unified diff right after the message.

Constraints

• Respect projector composition and the dog boundary: keeper owns commit:, graf owns diff:. Do NOT re-roll diff rendering inside keeper — link to (or invoke) graf's diff:.
• Read-only dog/HUNK stream for Bro; no mutation; all four URI slots still compose.

WIP

Design decisions

• Link vs inline: recommend the link — keeper stays diff-free, one clean dog boundary; inlining would force keeper to call graf or duplicate diff logic. (User leaning: link.)
• Link target = diff:?<sha> for the sha the commit: URI resolved to.

TODOs

• Decided: link (keeper stays diff-free).
• Localized: KEEPProjCommit (keeper/PROJ.c), diff: query form is the one that triggers graf's commit-show (# fragment renders empty).
• Implemented: append a diff:?<sha40> U tok32 click-target after the headers+message; Bro follows it (existing link primitive, no new dep).
• Test test/commit/01-diff-link.

Blockers and bummers

• A linked diff inherits whatever diff: shows — now fixed for sub-pin-bump commits by DIFF-001 (landed 018a59c4).

Outcome

• LANDED dac9dab7 — commit: appends a navigable diff:?<sha> link (query form) via bro's U click-target; keeper gains no diff logic / no graflib dep, dog boundary intact. 289/289 green.