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/config/default_config.yaml

@@ -28,6 +28,6 @@ mqtt:
 
 logging:
   format: "json"  # json or text
-  file: "logs/wled_controller.log"
+  file: "logs/ledgrab.log"
   max_size_mb: 100
   backup_count: 5

server/config/demo_config.yaml

@@ -1,5 +1,5 @@
 # Demo mode configuration
-# Loaded automatically when WLED_DEMO=true is set.
+# Loaded automatically when LEDGRAB_DEMO=true is set.
 # Uses isolated data directory (data/demo/) and a pre-configured API key
 # so the demo works out of the box with zero setup.
 
@@ -26,6 +26,6 @@ mqtt:
 
 logging:
   format: "text"
-  file: "logs/wled_controller.log"
+  file: "logs/ledgrab.log"
   max_size_mb: 100
   backup_count: 5

server/config/test_config.yaml

@@ -15,6 +15,6 @@ storage:
 
 logging:
   format: "text"
-  file: "logs/wled_test.log"
+  file: "logs/ledgrab_test.log"
   max_size_mb: 10
   backup_count: 2