broker/matrix-mxid GET: local_mxid_for_email was async-def but never awaited — response contained a coroutine and FastAPI 500'd ('coroutine object is not iterable'), so the dashboard silently showed no registered Matrix ID. Make it a plain sync def (blocking urllib).

app/main.py

@@ -2708,7 +2708,7 @@ async def broker_get_matrix_mxid(request: Request):
     return {"matrix_mxid": get_member_matrix_mxid(email), "local_mxid": local_mxid_for_email(email)}
 
 
-async def local_mxid_for_email(email: str) -> str:
+def local_mxid_for_email(email: str) -> str:
     """Resolve a member's local Matrix ID (@username:inference.coop), or '' if unknown."""
     import urllib.request
     try: