feat: restructure feature management and update project files

- Introduced a new `package-lock.json` to manage dependencies.
- Removed obsolete `.automaker/feature_list.json` and replaced it with a new structure under `.automaker/features/{id}/feature.json` for better organization.
- Updated various components to utilize the new features API for managing features, including creation, updates, and deletions.
- Enhanced the UI to reflect changes in feature management, including updates to the sidebar and board view.
- Improved documentation and comments throughout the codebase to clarify the new feature management process.

app/electron/auto-mode-service.js

@@ -90,7 +90,7 @@ class AutoModeService {
       content: `Working in isolated branch: ${result.branchName}\n`,
     });
 
-    // Update feature with worktree info in feature_list.json
+    // Update feature with worktree info
     await featureLoader.updateFeatureWorktree(
       feature.id,
       projectPath,