fix(prometheus): a refused token stops the scraping, as Home Assistant bans an address after a few refusals (#6355)

Also names the Home Assistant connection by its address in the audit log and
timeline, where its id showed.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/integration/test_prometheus_scrape.py

@@ -134,3 +134,38 @@ def test_a_scrape_records_series_rates_and_a_down_target_fires_its_rule(app):
     assert rows[down].last_ok_at is None
     assert down_latest[(down, "is_up")] == 0.0
     assert state.state == AlertStateEnum.firing
+
+
+def test_a_refused_token_is_asked_once(app):
+    """Home Assistant bans an address after a few refusals, so a refused token
+    isn't retried at each interval, however long ago the last scrape was."""
+    from sqlalchemy import select
+
+    scheduler = _prom("scheduler")
+    PrometheusTarget = _prom("models").PrometheusTarget
+    TokenRefused = _prom("scraper").TokenRefused
+    name = f"refused-{uuid.uuid4().hex[:8]}"
+    asked = []
+
+    async def fake_scrape(url, token, verify_tls):
+        asked.append(url)
+        raise TokenRefused("Answered 401: the token was refused.")
+
+    async def go():
+        async with app.db_sessionmaker() as s:
+            async with s.begin():
+                s.add(PrometheusTarget(name=name, url=f"http://{name}/metrics"))
+        await scheduler.scrape_due(app, scrape=fake_scrape)
+        async with app.db_sessionmaker() as s:
+            async with s.begin():
+                row = (await s.execute(select(PrometheusTarget).where(PrometheusTarget.name == name))).scalar_one()
+                refused = row.refused
+                row.last_scraped_at = row.last_scraped_at.replace(year=2000)
+        await scheduler.scrape_due(app, scrape=fake_scrape)
+        async with app.db_sessionmaker() as s:
+            async with s.begin():
+                await s.delete((await s.execute(select(PrometheusTarget).where(PrometheusTarget.name == name))).scalar_one())
+        return refused
+
+    assert asyncio.run(go()) is True
+    assert asked == [f"http://{name}/metrics"]