Add full-image lightbox and restore WLED state on stop

- Add GET /picture-streams/full-image endpoint to serve full-res images
- Click static image preview thumbnail to open full-res lightbox
- Snapshot WLED state (on/off, lor, AudioReactive) before streaming
- Restore saved WLED state when streaming stops

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

server/src/wled_controller/core/processor_manager.py

@@ -120,6 +120,8 @@ class ProcessorState:
     # Capture libraries (BetterCam, MSS, DXcam) use thread-local state,
     # so all calls must run on the same thread.
     capture_executor: Optional[concurrent.futures.ThreadPoolExecutor] = None
+    # WLED state snapshot taken before streaming starts (to restore on stop)
+    wled_state_before: Optional[dict] = None
 
 
 class ProcessorManager:
@@ -401,6 +403,24 @@ class ProcessorManager:
         # Resolve stream settings
         self._resolve_stream_settings(state)
 
+        # Snapshot WLED state before streaming changes it
+        try:
+            async with httpx.AsyncClient(timeout=5) as http:
+                resp = await http.get(f"{state.device_url}/json/state")
+                resp.raise_for_status()
+                wled_state = resp.json()
+                state.wled_state_before = {
+                    "on": wled_state.get("on", True),
+                    "lor": wled_state.get("lor", 0),
+                }
+                # AudioReactive is optional (usermod)
+                if "AudioReactive" in wled_state:
+                    state.wled_state_before["AudioReactive"] = wled_state["AudioReactive"]
+                logger.info(f"Saved WLED state before streaming: {state.wled_state_before}")
+        except Exception as e:
+            logger.warning(f"Could not snapshot WLED state: {e}")
+            state.wled_state_before = None
+
         # Connect to WLED device
         try:
             use_ddp = state.led_count > 500
@@ -488,6 +508,19 @@ class ProcessorManager:
                 pass
             state.task = None
 
+        # Restore WLED state that was changed when streaming started
+        if state.wled_state_before:
+            try:
+                async with httpx.AsyncClient(timeout=5) as http:
+                    await http.post(
+                        f"{state.device_url}/json/state",
+                        json=state.wled_state_before,
+                    )
+                logger.info(f"Restored WLED state: {state.wled_state_before}")
+            except Exception as e:
+                logger.warning(f"Could not restore WLED state: {e}")
+            state.wled_state_before = None
+
         # Close WLED connection
         if state.wled_client:
             await state.wled_client.close()