Annotate generate_bulletin return type so Gradio routes 2 outputs

@app .api infers output count from the return annotation; without one
Gradio assumed 0 outputs and dropped (status, html) on the floor, so
the frontend never received any payload and stayed on Connecting....

app.py

@@ -7,6 +7,7 @@ from the original Blocks app.
 
 import os
 from pathlib import Path
+from typing import Iterator
 
 from fastapi.responses import HTMLResponse
 from gradio import Server
@@ -28,7 +29,9 @@ def _owner_from(repo_id: str) -> str:
 
 
 @app.api(name="generate_bulletin", concurrency_limit=1)
-def generate_bulletin(repo_id: str, max_sessions: int):
+def generate_bulletin(
+    repo_id: str, max_sessions: int
+) -> Iterator[tuple[str, str]]:
     """Streams (status, html) updates; final tick carries the bulletin HTML."""
 
     yield "Connecting…", empty_bulletin_html("Connecting…")