Add Git action modal with custom commit message support

- Add a Git action confirmation modal with live commit/push/PR progress states
- Accept optional `commitMessage` input and skip AI message generation when provided
- Expand server and contracts tests for custom commit message handling

Co-authored-by: codex <codex@users.noreply.github.com>
36bc85f54dJulius Marminge committed on 2/12/2026, 8:22:05 PMparent3c939e8
5 files changedLine totals unavailable