Use tuple[str,str] return annotation so Gradio counts 2 outputs

Iterator[tuple[...]] confused @app .api's output-count inference.
Annotating the yielded shape directly matches how Gradio Blocks handles
streaming generators.

app.py

@@ -7,7 +7,6 @@ from the original Blocks app.
 
 import os
 from pathlib import Path
-from typing import Iterator
 
 from fastapi.responses import HTMLResponse
 from gradio import Server
@@ -31,7 +30,7 @@ def _owner_from(repo_id: str) -> str:
 @app.api(name="generate_bulletin", concurrency_limit=1)
 def generate_bulletin(
     repo_id: str, max_sessions: int
-) -> Iterator[tuple[str, str]]:
+) -> tuple[str, str]:
     """Streams (status, html) updates; final tick carries the bulletin HTML."""
 
     yield "Connecting…", empty_bulletin_html("Connecting…")