feat: enhance worktree listing by scanning external directories

- Implemented a new function to scan the .worktrees directory for worktrees that may exist outside of git's management, allowing for better detection of externally created or corrupted worktrees.
- Updated the /list endpoint to include discovered worktrees in the response, improving the accuracy of the worktree listing.
- Added logging for discovered worktrees to aid in debugging and tracking.
- Cleaned up and organized imports in the list.ts file for better maintainability.

apps/ui/src/components/views/graph-view/graph-view.tsx

@@ -44,7 +44,7 @@ export function GraphView({
   const { currentProject } = useAppStore();
 
   // Use the same background hook as the board view
-  const { backgroundImageStyle } = useBoardBackground({ currentProject });
+  const { backgroundImageStyle, backgroundSettings } = useBoardBackground({ currentProject });
 
   // Filter features by current worktree (same logic as board view)
   const filteredFeatures = useMemo(() => {
@@ -213,6 +213,7 @@ export function GraphView({
         nodeActionCallbacks={nodeActionCallbacks}
         onCreateDependency={handleCreateDependency}
         backgroundStyle={backgroundImageStyle}
+        backgroundSettings={backgroundSettings}
         className="h-full"
       />
     </div>