v9.5: 實作標籤完全不重疊算法

- 新增 _calculate_lane_conflicts_v2() 分開返回標籤重疊和線穿框分數
- 修改泳道選擇算法，優先選擇無標籤重疊的泳道
- 兩階段搜尋：優先側別無可用泳道則嘗試另一側
- 增強日誌輸出，顯示標籤範圍和詳細衝突分數

🤖 Generated with Claude Code
Co-Authored-By: Claude <noreply@anthropic.com>

start_dev.bat

@@ -0,0 +1,27 @@
+@echo off
+echo ========================================
+echo TimeLine Designer - Development Server
+echo ========================================
+echo.
+echo Starting Backend (FastAPI on port 8000)...
+start "Backend Server" cmd /k "conda activate timeline_designer && cd /d %~dp0 && uvicorn backend.main:app --reload --host 0.0.0.0 --port 8000"
+
+timeout /t 3 /nobreak
+
+echo.
+echo Starting Frontend (React + Vite on port 12010)...
+start "Frontend Server" cmd /k "cd /d %~dp0frontend-react && npm run dev"
+
+echo.
+echo ========================================
+echo Servers starting...
+echo Backend:  http://localhost:8000
+echo Frontend: http://localhost:12010
+echo API Docs: http://localhost:8000/api/docs
+echo ========================================
+echo.
+echo Press any key to stop all servers...
+pause >nul
+
+taskkill /FI "WindowTitle eq Backend Server*" /T /F
+taskkill /FI "WindowTitle eq Frontend Server*" /T /F