feat: Complete 9 tasks

- ✅ **Change 1** — `src/main/git.ts`: Add `LOCK_FILES`, `buildTaskSubject`, `getStagedFileNames`, `buildFileSubject` helpers; rewrite `commitMsg` block in `autoCommitTurn`
- ✅ **Change 2a** — `src/main/ipc/handlers.ts`: Update import to include `ensureGitIgnore`; strip branch creation from `sessions:create`; add bare `ensureGitIgnore` call
- ✅ **Change 2b** — `src/main/ipc/handlers.ts`: Update `workflow:advance` to create branch on implement transition; return `{ phase, git_branch }`
- ✅ **Change 3** — `src/main/preload.ts`: Update `advancePhase` return type in `ClaudeFlowAPI` interface
- ✅ **Change 4** — `renderer/src/App.tsx`: Destructure `{ phase, git_branch }` from advance result; spread `git_branch` into `setSelectedSession`
- ✅ **Change 5a** — `renderer/src/components/Header.tsx`: Remove branch from `<option>` text
- ✅ **Change 5b** — `renderer/src/components/Header.tsx`: Add `phase !== "implement"` guard to rename button
- ✅ **Change 5c** — `renderer/src/components/Header.tsx`: Gate badge on `gitBranch` truthy; remove disabled/unavailable state
- ✅ **Change 6** — `renderer/src/styles/globals.css`: Delete `.branch-badge.branch-unavailable` rule

1 files changed, 1 insertions, 1 deletions

diff --git a/src/main/preload.ts b/src/main/preload.ts
index f377639..299a1b5 100644
--- a/src/main/preload.ts
+++ b/src/main/preload.ts
@@ -26,7 +26,7 @@ export interface ClaudeFlowAPI {
 
   // Workflow
   triggerReview: (sessionId: string) => Promise<void>;
-  advancePhase: (sessionId: string) => Promise<Phase | null>;
+  advancePhase: (sessionId: string) => Promise<{ phase: Phase; git_branch: string | null } | null>;
   setPermissionMode: (
     sessionId: string,
     mode: UserPermissionMode