fix: add retry limit to startup wait loops to prevent infinite hang

Each service wait loop now fails after 30 retries (~60s) instead of
spinning forever when a port is occupied by a stuck process.
Also added cleanup label that kills partially-started services on failure.

start.bat

@@ -29,10 +29,21 @@ start "jrxml-validator" /MIN .venv\Scripts\python.exe -c "import uvicorn; uvicor
 
 :: 等待验证服务就绪 (用 PowerShell 检测)
 echo [等待] 验证服务就绪...
+set /a RETRY=0
 :wait_val
 ping -n 2 127.0.0.1 >nul
 powershell -Command "try{$r=Invoke-WebRequest -Uri http://localhost:8001/health -TimeoutSec 2 -UseBasicParsing;exit 0}catch{exit 1}" >nul 2>&1
-if errorlevel 1 goto wait_val
+if not errorlevel 1 goto val_ok
+set /a RETRY+=1
+if %RETRY% GEQ 30 (
+    echo    [失败] 验证服务启动超时，请检查端口 8001 是否被占用
+    taskkill /F /FI "WINDOWTITLE eq jrxml-validator*" >nul 2>&1
+    for /f "tokens=5" %%a in ('netstat -ano ^| findstr ":8001.*LISTENING"') do taskkill /F /PID %%a >nul 2>&1
+    pause
+    exit /b 1
+)
+goto wait_val
+:val_ok
 echo    :8001 就绪
 
 :: 启动 API 服务 (前台，Ctrl+C 退出)