feat: Add remote sync for project clones

Fetch remote changes before agents start working so they build on
up-to-date code. Adds ProjectSyncManager with git fetch + ff-only
merge of defaultBranch, integrated into phase dispatch to sync
before branch creation.

- Schema: lastFetchedAt column on projects table (migration 0029)
- Events: project:synced, project:sync_failed
- Phase dispatch: sync all linked projects before creating branches
- tRPC: syncProject, syncAllProjects, getProjectSyncStatus
- CLI: cw project sync [name] --all, cw project status [name]
- Frontend: sync button + ahead/behind badge on projects settings

apps/server/agent/process-manager.test.ts

@@ -132,7 +132,7 @@ describe('ProcessManager', () => {
 
       // Mock project repository
       vi.mocked(mockProjectRepository.findProjectsByInitiativeId).mockResolvedValue([
-        { id: '1', name: 'project1', url: 'https://github.com/user/project1.git', defaultBranch: 'main', createdAt: new Date(), updatedAt: new Date() }
+        { id: '1', name: 'project1', url: 'https://github.com/user/project1.git', defaultBranch: 'main', lastFetchedAt: null, createdAt: new Date(), updatedAt: new Date() }
       ]);
 
       // Mock existsSync to return true for worktree paths