Add auto-start targets feature with dashboard section

- Add auto_start boolean field to PictureTarget model (persisted per-target)
- Wire auto_start through API schemas, routes, and store
- Auto-start targets on server boot in main.py lifespan
- Add star toggle button on target cards (next to delete button)
- Add auto-start section on dashboard between performance and profiles
- Remove auto-start section from profiles tab

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/src/wled_controller/api/routes/picture_targets.py

@@ -101,6 +101,7 @@ def _target_to_response(target) -> PictureTargetResponse:
             keepalive_interval=target.keepalive_interval,
             state_check_interval=target.state_check_interval,
             description=target.description,
+            auto_start=target.auto_start,
             created_at=target.created_at,
             updated_at=target.updated_at,
         )
@@ -112,6 +113,7 @@ def _target_to_response(target) -> PictureTargetResponse:
             picture_source_id=target.picture_source_id,
             key_colors_settings=_kc_settings_to_schema(target.settings),
             description=target.description,
+            auto_start=target.auto_start,
             created_at=target.created_at,
             updated_at=target.updated_at,
         )
@@ -121,6 +123,7 @@ def _target_to_response(target) -> PictureTargetResponse:
             name=target.name,
             target_type=target.target_type,
             description=target.description,
+            auto_start=target.auto_start,
             created_at=target.created_at,
             updated_at=target.updated_at,
         )
@@ -159,6 +162,7 @@ async def create_target(
             picture_source_id=data.picture_source_id,
             key_colors_settings=kc_settings,
             description=data.description,
+            auto_start=data.auto_start,
         )
 
         # Register in processor manager
@@ -274,6 +278,7 @@ async def update_target(
             state_check_interval=data.state_check_interval,
             key_colors_settings=kc_settings,
             description=data.description,
+            auto_start=data.auto_start,
         )
 
         # Detect KC brightness VS change (inside key_colors_settings)