refac: web/rag config

backend/start_windows.bat

@@ -7,8 +7,8 @@ SET "SCRIPT_DIR=%~dp0"
 cd /d "%SCRIPT_DIR%" || exit /b
 
 :: Add conditional Playwright browser installation
-IF /I "%RAG_WEB_LOADER_ENGINE%" == "playwright" (
-    IF "%PLAYWRIGHT_WS_URI%" == "" (
+IF /I "%WEB_LOADER_ENGINE%" == "playwright" (
+    IF "%PLAYWRIGHT_WS_URL%" == "" (
         echo Installing Playwright browsers...
         playwright install chromium
         playwright install-deps chromium