Summary

• add git and branch changes as review sources in the app, make git changes the default, and keep the desktop review tree in sync with the selected source
• extend the opencode VCS API to expose uncommitted diffs and branch diffs against the detected default branch, including clean empty states and branch visibility rules
• introduce a shared Git service, route existing git callsites through it, and move reusable git parsing/default-branch primitives out of Vcs

Testing

• bun typecheck (packages/opencode)
• bun typecheck (packages/app)
• bun test test/project/vcs.test.ts test/project/project.test.ts test/server/project-init-git.test.ts (packages/opencode)
• bun test --preload ./happydom.ts ./src/context/global-sync/event-reducer.test.ts (packages/app)