fix(freebuff): derive commit summaries from git changes

[victorxheng]

User request

A Freebuff cloud user reported that commits shown in the Git tab after pushing use the original prompt text as the commit description instead of a meaningful summary of the actual project changes. The attached screenshot showed prompt-derived commit titles such as Freebuff: Add this below the AI instructions... and Before: When committing changes....

Implementation

• Added summarizeGitChangesForCommit, a deterministic shared helper that builds concise commit titles from git status/diff paths instead of user prompt text.
• Covered the reported case with a unit test: modified AGENTS.md plus new CHANGELOG.md now summarizes as Update AI agent instructions and add changelog.
• Strengthened the commit tool guide so agent-created commits explicitly base title/body on actual git status/diff and never copy/truncate the original prompt.
• Updated the example git-committer agent instructions to follow the same rule.

Validation

• bun test common/src/util/__tests__/git-commit-summary.test.ts
• cd common && bun run typecheck
• git diff --check

Confidence

Ready for review. The exact cloud Git-tab route is not present in this public snapshot, so this PR places the fix in shared code and the commit-generation contract that cloud/private code can call or inherit. The covered behavior directly matches the user report and prevents prompt-only summaries in the shared agent commit path.

The prompt-string edits in run-terminal-command.ts and 02-intermediate-git-committer.ts are sensible, low-risk clarifications telling the agent to derive commit messages from git status/diff rather than the user's prompt. Those are fine as-is and easy to port.

The core of the PR, summarizeGitChangesForCommit in common/src/util/git-commit-summary.ts, is the problem. It's 175 lines of new logic plus 40 lines of tests, but nothing in this diff calls it — it's exercised only by its own test file. The PR description confirms this directly: "The exact cloud Git-tab route is not present in this public snapshot, so this PR places the fix in shared code... that cloud/private code can call or inherit." That means this doesn't actually fix the reported bug (prompt text showing up as commit titles in the cloud Git tab); it's a speculative function sitting in common/src/util/ waiting for something to call it, which nothing here does. The reported issue is almost certainly in the push/commit-summary path used by cloud, not in the agent's run_terminal_command git-commit flow this PR touches — those are two different mechanisms (one is an LLM writing a commit message via the tool prompt, the other is presumably a non-LLM summary generated at push time).

As it stands, a maintainer porting this would get dead code with no call site, plus two small prompt tweaks that may or may not be relevant to the actual bug. I'd split this: drop the unused helper/tests, or find the actual call site in the private repo and wire it in with a real integration point and test that exercises the actual bug path, not a synthetic one.

Apologies — this PR was auto-closed by GitHub when we force-pushed a history rewrite of this repository (repository maintenance; every commit SHA changed). That was not a judgment on this PR, and GitHub does not allow us to reopen it because the commits it was based on no longer exist in the new history.

If you'd like to continue with this change: rebase your branch onto the new main (or recreate it from a fresh clone) and open a new PR — feel free to link back to this one for context, and we'll pick up the review there.

Sorry for the churn, and thanks for contributing.