feat(server,frontend): real-time sync architecture with message accumulator

- Add message-accumulator.js: cascades diff-based message accumulation
- Add 3-second cascade polling with broadcastToAll (was undefined!)
- Add /api/bridge/approve endpoint: tries accept/reject Step→Command→Terminal
- Add persistent approve/reject buttons in chat header toolbar
- Frontend: loadSessionMessages (trajectory + accumulated), applyNewMessages (WS push)
- Status change detection: _prevStatusKey tracking prevents unnecessary re-renders
- actionInProgress flag prevents DOM replacement during button fetch
- Known issues: Trajectory 341 hard limit, Cascade no command-approval state

.agents/workflows/check-vikunja.md

@@ -12,27 +12,27 @@ description: Vikunja API로 gravity_web 프로젝트 태스크 현황을 조회
 
 1. 전체 목록:
 ```powershell
-python .agents\workflows\helpers\vikunja_helper.py list
+C:\ProgramData\miniforge3\envs\gravity_web\python.exe .agents\workflows\helpers\vikunja_helper.py list
 ```
 
 2. TODO만:
 ```powershell
-python .agents\workflows\helpers\vikunja_helper.py list todo
+C:\ProgramData\miniforge3\envs\gravity_web\python.exe .agents\workflows\helpers\vikunja_helper.py list todo
 ```
 
 3. DONE만:
 ```powershell
-python .agents\workflows\helpers\vikunja_helper.py list done
+C:\ProgramData\miniforge3\envs\gravity_web\python.exe .agents\workflows\helpers\vikunja_helper.py list done
 ```
 
 4. 태스크 완료 처리 (**⚠️ 반드시 이 방법 사용 — 직접 API 호출 금지**):
 ```powershell
-python .agents\workflows\helpers\vikunja_helper.py done {TASK_ID}
+C:\ProgramData\miniforge3\envs\gravity_web\python.exe .agents\workflows\helpers\vikunja_helper.py done {TASK_ID}
 ```
 
 5. 새 태스크 생성:
 ```powershell
-python .agents\workflows\helpers\vikunja_helper.py create "제목" "설명" --labels Backend,Priority:High
+C:\ProgramData\miniforge3\envs\gravity_web\python.exe .agents\workflows\helpers\vikunja_helper.py create "제목" "설명" --labels Backend,Priority:High
 ```
 
 > [!CAUTION]