fix: resolve merge conflicts and clean up expand project feature

Post-merge fixes for PR #36 (expand-project-with-ai):

- Fix syntax error in App.tsx Escape handler (missing `} else`)
- Fix missing closing brace in types.ts FeatureBulkCreateResponse
- Remove unused exception variables flagged by ruff (F841)
- Make nav buttons minimalist: remove text labels, keep icons + shortcuts
  - "Add Feature" → icon + N shortcut, tooltip "Add new feature"
  - "Expand" → icon + E shortcut, tooltip "Expand project with AI"

All checks pass: ruff, security tests, ESLint, TypeScript build.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

server/routers/expand_project.py

@@ -238,7 +238,7 @@ async def expand_project_websocket(websocket: WebSocket, project_name: str):
     except WebSocketDisconnect:
         logger.info(f"Expand chat WebSocket disconnected for {project_name}")
 
-    except Exception as e:
+    except Exception:
         logger.exception(f"Expand chat WebSocket error for {project_name}")
         try:
             await websocket.send_json({