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/tests/core/test_mapping_adapter.py

@@ -5,7 +5,7 @@ from pathlib import Path
 
 import pytest
 
-from wled_controller.core.game_integration.mapping_adapter import (
+from ledgrab.core.game_integration.mapping_adapter import (
     MappingAdapter,
     load_adapter_from_yaml,
     validate_adapter_yaml,