feat(worktree): add AI commit message generation feature

- Implemented a new endpoint to generate commit messages based on git diffs.
- Updated worktree routes to include the AI commit message generation functionality.
- Enhanced the UI to support automatic generation of commit messages when the commit dialog opens, based on user settings.
- Added settings for enabling/disabling AI-generated commit messages and configuring the model used for generation.

apps/ui/src/components/views/settings-view/model-defaults/model-defaults-section.tsx

@@ -28,6 +28,11 @@ const QUICK_TASKS: PhaseConfig[] = [
     label: 'Image Descriptions',
     description: 'Analyzes and describes context images',
   },
+  {
+    key: 'commitMessageModel',
+    label: 'Commit Messages',
+    description: 'Generates git commit messages from diffs',
+  },
 ];
 
 const VALIDATION_TASKS: PhaseConfig[] = [