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/main.py

@@ -147,6 +147,19 @@ async def lifespan(app: FastAPI):
     # Start profile engine (evaluates conditions and auto-starts/stops targets)
     await profile_engine.start()
 
+    # Auto-start targets with auto_start=True
+    auto_started = 0
+    for target in targets:
+        if getattr(target, "auto_start", False):
+            try:
+                await processor_manager.start_processing(target.id)
+                auto_started += 1
+                logger.info(f"Auto-started target: {target.name} ({target.id})")
+            except Exception as e:
+                logger.warning(f"Failed to auto-start target {target.id}: {e}")
+    if auto_started:
+        logger.info(f"Auto-started {auto_started} target(s)")
+
     yield
 
     # Shutdown