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/storage/test_base_store.py

@@ -7,7 +7,7 @@ from pathlib import Path
 
 import pytest
 
-from wled_controller.storage.base_store import BaseJsonStore, EntityNotFoundError
+from ledgrab.storage.base_store import BaseJsonStore, EntityNotFoundError
 
 
 # ---------------------------------------------------------------------------
@@ -45,6 +45,7 @@ class _TestStore(BaseJsonStore[_Item]):
 
 class _LegacyStore(BaseJsonStore[_Item]):
     """Store that supports legacy JSON keys for migration testing."""
+
     _json_key = "items_v2"
     _entity_name = "Item"
     _legacy_json_keys = ["items_v1", "old_items"]