Add MQTT publish request and response models, and implement publish route

- Introduced MQTTPublishRequest and MQTTPublishResponse models for handling MQTT message publishing.
- Implemented a new POST route for publishing MQTT messages, including error handling and logging.
- Enhanced the StandaloneAutoRecorder with improved logging during manual recording start.
- Updated the frontend to include an MQTT Debug Panel for better monitoring and debugging capabilities.

media-api/main.py

@@ -20,10 +20,10 @@ transcoding_semaphore = threading.Semaphore(MAX_CONCURRENT_TRANSCODING)
 
 app = FastAPI(title="Media API", version="0.1.0")
 
-# CORS for dashboard at exp-dash:8080 (and localhost for convenience)
+# CORS for dashboard - allow all origins to support access from different IPs/hostnames
 app.add_middleware(
     CORSMiddleware,
-    allow_origins=["http://exp-dash:8080", "http://localhost:8080"],
+    allow_origins=["*"],  # Allow all origins for flexibility
     allow_credentials=True,
     allow_methods=["*"],
     allow_headers=["*"]
@@ -143,15 +143,25 @@ def get_video_mime_type(path: pathlib.Path) -> str:
     return mime_types.get(ext, "video/mp4")
 
 
-def open_file_range(path: pathlib.Path, start: int, end: Optional[int]):
+def generate_file_range(path: pathlib.Path, start: int, end: Optional[int], chunk_size: int = 8192):
+    """
+    Generator that yields file chunks in a memory-efficient way.
+    This prevents MemoryError when streaming large video files.
+    """
     file_size = path.stat().st_size
     if end is None or end >= file_size:
         end = file_size - 1
-    length = end - start + 1
+    
+    remaining = end - start + 1
     with open(path, 'rb') as f:
         f.seek(start)
-        chunk = f.read(length)
-    return chunk, file_size, start, end
+        while remaining > 0:
+            read_size = min(chunk_size, remaining)
+            chunk = f.read(read_size)
+            if not chunk:
+                break
+            yield chunk
+            remaining -= len(chunk)
 
 
 @app.head("/videos/{file_id:path}/stream")
@@ -212,14 +222,22 @@ def stream_file(request: Request, file_id: str):
     if start > end:
         raise HTTPException(status_code=416, detail="Range Not Satisfiable")
     
-    chunk, size, actual_start, actual_end = open_file_range(p, start, end)
+    # Calculate content length
+    content_length = end - start + 1
     
+    # Use streaming response to avoid loading entire chunk into memory
+    # This prevents MemoryError for large video files
     headers = {
         **base_headers,
-        "Content-Range": f"bytes {actual_start}-{actual_end}/{size}",
-        "Content-Length": str(len(chunk)),
+        "Content-Range": f"bytes {start}-{end}/{file_size}",
+        "Content-Length": str(content_length),
     }
-    return Response(content=chunk, status_code=206, headers=headers)
+    return StreamingResponse(
+        generate_file_range(p, start, end),
+        media_type=content_type,
+        headers=headers,
+        status_code=206
+    )
 
 # Convenience endpoint: pass file_id via query instead of path (accepts raw or URL-encoded)
 @app.head("/videos/stream")