Implement Monlet MVP stack and UI updates

server/monlet_server/middleware/body_limit.py

@@ -0,0 +1,32 @@
+from starlette.middleware.base import BaseHTTPMiddleware
+from starlette.requests import Request
+
+from ..errors import error_response
+from ..settings import get_settings
+
+
+class BodyLimitMiddleware(BaseHTTPMiddleware):
+    async def dispatch(self, request: Request, call_next):
+        limit = get_settings().body_limit_bytes
+        cl = request.headers.get("content-length")
+        if cl is not None:
+            try:
+                if int(cl) > limit:
+                    return error_response(request, 413, "payload_too_large", "body too large")
+            except ValueError:
+                return error_response(request, 400, "validation", "invalid content-length")
+            return await call_next(request)
+
+        total = 0
+        chunks: list[bytes] = []
+        async for chunk in request.stream():
+            total += len(chunk)
+            if total > limit:
+                return error_response(request, 413, "payload_too_large", "body too large")
+            chunks.append(chunk)
+
+        async def receive():
+            return {"type": "http.request", "body": b"".join(chunks), "more_body": False}
+
+        request._receive = receive  # type: ignore[attr-defined]
+        return await call_next(request)