[Bug]: Diffs/checkpoints not shown when workspace cwd is a subdirectory of a git repo

[imabdulazeez]

Before submitting

• I searched existing issues and did not find a duplicate.
• I included enough detail to reproduce or investigate the problem.

Area

apps/web

Steps to reproduce

1. Have a git repository at /path/to/repo (so /path/to/repo/.git exists).
2. Configure a project/open a workspace whose cwd is a sub-package, e.g. /path/to/repo/apps/server.
3. Start a thread, let the agent edit files.
4. Open the diff / checkpoint panel.

Expected behavior

Per-turn diffs should appear in the diff panel and checkpoints should be captured, the same way they do when the workspace is opened at the repo root. Running git status from that same cwd in a terminal works fine, so t3code should treat it as a git workspace too.

Actual behavior

The diff panel stays empty and no checkpoints are recorded for the thread. Git-backed features silently no-op, with no UI hint that the workspace was classified as non-git.

Impact

Major degradation or frequent failure

Version or commit

main @ 17b4396 and 0.0.22-nightly.20260501.170 (17b4396)

Environment

macOS 15.7.3 (arm64), Node v22.22.2, Bun 1.3.13

Logs or stack traces

Screenshots, recordings, or supporting files

No response

Workaround

No response