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/api/routes.py

@@ -10,7 +10,8 @@ from typing import List, Dict, Any
 import httpx
 import numpy as np
 from PIL import Image
-from fastapi import APIRouter, HTTPException, Depends
+from fastapi import APIRouter, HTTPException, Depends, Query
+from fastapi.responses import Response
 
 from wled_controller import __version__
 from wled_controller.api.auth import AuthRequired
@@ -1612,6 +1613,38 @@ async def validate_image(
         return ImageValidateResponse(valid=False, error=str(e))
 
 
+@router.get("/api/v1/picture-streams/full-image", tags=["Picture Streams"])
+async def get_full_image(
+    _auth: AuthRequired,
+    source: str = Query(..., description="Image URL or local file path"),
+):
+    """Serve the full-resolution image for lightbox preview."""
+    from pathlib import Path
+
+    try:
+        if source.startswith(("http://", "https://")):
+            async with httpx.AsyncClient(timeout=15, follow_redirects=True) as client:
+                response = await client.get(source)
+                response.raise_for_status()
+                pil_image = Image.open(io.BytesIO(response.content))
+        else:
+            path = Path(source)
+            if not path.exists():
+                raise HTTPException(status_code=404, detail="File not found")
+            pil_image = Image.open(path)
+
+        pil_image = pil_image.convert("RGB")
+        buf = io.BytesIO()
+        pil_image.save(buf, format="JPEG", quality=90)
+        buf.seek(0)
+        return Response(content=buf.getvalue(), media_type="image/jpeg")
+
+    except HTTPException:
+        raise
+    except Exception as e:
+        raise HTTPException(status_code=400, detail=str(e))
+
+
 @router.post("/api/v1/picture-streams", response_model=PictureStreamResponse, tags=["Picture Streams"], status_code=201)
 async def create_picture_stream(
     data: PictureStreamCreate,