test(alerts): check the history's Action column on one rule's rows, which the test owns (#5316)

The all-rules page reads a Postgres shared with other tests, whose
Ansible-run events turn the column on.

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

tests/integration/test_alert_history_page.py

@@ -73,13 +73,16 @@ def test_a_viewer_reads_the_alert_history(app):
         assert '98% <span class="tone-dim">(fires above 90%)</span>' in page
         assert "email failed" in page and f"mx-{tag}: timed out" in page and "webhook sent" in page
         assert f"muted · patch-{tag}" in page and "No CPU reading" in page and "2 changes of state" in page
-        assert "<th>Rule</th>" in page and "<th>Notified</th>" in page and "<th>Action</th>" not in page
+        assert "<th>Rule</th>" in page and "<th>Notified</th>" in page
 
         resp = await client.get(f"/alerts/history?range=24h&rule={hot_id}", headers={"HX-Request": "true"})
         rows = await resp.get_data(as_text=True)
         assert "<html" not in rows and "<table" in rows
         assert f"old-{tag}" in rows and f"cold-note-{tag}" not in rows
         assert "<th>Rule</th>" not in rows                                   # one rule: no column for it
+        # Columns only for what this rule's rows hold: it told someone, it ran
+        # nothing. (The all-rules page shares Postgres with other tests' runs.)
+        assert "<th>Notified</th>" in rows and "<th>Action</th>" not in rows
         assert "Fired 1 time</strong> in the last 24h" in rows                # its verdict
 
         # The next page as the reader scrolls: only older rows, without the table