refactor: rename project to LedGrab, split HA integration into separate repo

- Rename Python package: wled_controller -> ledgrab
- Rename env var prefix: WLED_ -> LEDGRAB_ (with auto-migration for old vars)
- Rename localStorage key: wled_api_key -> ledgrab_api_key (with migration)
- Rename HA integration domain: wled_screen_controller -> ledgrab
- Update all imports, build scripts, Docker, installer, config, docs
- Remove HA integration (moved to ledgrab-haos-integration repo)
- Remove hacs.json (belongs in HA repo now)
- Add startup warning for users with old WLED_ env vars
- All tests pass (715/715), ruff clean, tsc clean, frontend builds

server/scripts/stop-server.bat

@@ -1,13 +1,13 @@
 @echo off
-REM WLED Screen Controller Stop Script
+REM LedGrab Stop Script
 REM This script stops the running WLED screen controller server
 
-echo Stopping WLED Screen Controller...
+echo Stopping LedGrab...
 echo.
 
-REM Find and kill Python processes running wled_controller.main
+REM Find and kill Python processes running ledgrab.main
 for /f "tokens=2" %%i in ('tasklist /FI "IMAGENAME eq python.exe" /FO LIST ^| findstr /B "PID:"') do (
-    wmic process where "ProcessId=%%i" get CommandLine 2>nul | findstr /C:"wled_controller.main" >nul
+    wmic process where "ProcessId=%%i" get CommandLine 2>nul | findstr /C:"ledgrab.main" >nul
     if not errorlevel 1 (
         taskkill /PID %%i /F
         echo WLED controller process (PID %%i) terminated.
@@ -15,5 +15,5 @@ for /f "tokens=2" %%i in ('tasklist /FI "IMAGENAME eq python.exe" /FO LIST ^| fi
 )
 
 echo.
-echo Done! WLED Screen Controller stopped.
+echo Done! LedGrab stopped.
 pause