fix: 12h cooldown before reopening manually closed host_silence (0.9.9)

Track resolved_by on problems; suppress scan/ingest recreate after manual
resolve; reopen same problem after cooldown; auto-close via heartbeat unchanged.

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/tests/test_problem_rules.py

@@ -182,3 +182,99 @@ def test_heartbeat_resolves_host_silence(db_session, rule_settings):
     maybe_create_problem(db_session, fresh_hb)
     db_session.refresh(open_silence)
     assert open_silence.status == "resolved"
+    assert open_silence.resolved_by == "auto"
+
+
+def test_host_silence_suppressed_after_manual_resolve_on_ingest(db_session, rule_settings, monkeypatch):
+    monkeypatch.setenv("SAC_HOST_SILENCE_MANUAL_RESOLVE_COOLDOWN_HOURS", "12")
+    get_settings.cache_clear()
+
+    hb = _ingest(
+        db_session,
+        type="agent.heartbeat",
+        category="agent",
+        severity="info",
+        title="hb",
+        summary="heartbeat",
+    )
+    hb.received_at = datetime.now(timezone.utc) - timedelta(hours=2)
+    db_session.flush()
+
+    trigger = _ingest(
+        db_session,
+        type="ssh.login.success",
+        severity="info",
+        title="ok",
+        summary="login",
+    )
+    problem, created = maybe_create_problem(db_session, trigger)
+    assert created is True
+    problem.status = "resolved"
+    problem.resolved_by = "manual"
+    problem.updated_at = datetime.now(timezone.utc)
+    db_session.flush()
+
+    trigger2 = _ingest(
+        db_session,
+        type="ssh.login.success",
+        severity="info",
+        title="ok2",
+        summary="login2",
+    )
+    problem2, created2 = maybe_create_problem(db_session, trigger2)
+    assert problem2 is None
+    assert created2 is False
+
+    open_silence = db_session.scalar(
+        select(Problem).where(
+            Problem.rule_id == RULE_HOST_SILENCE,
+            Problem.status == "open",
+        )
+    )
+    assert open_silence is None
+
+
+def test_host_silence_reopens_after_auto_resolve_when_still_stale(db_session, rule_settings, monkeypatch):
+    monkeypatch.setenv("SAC_HOST_SILENCE_MANUAL_RESOLVE_COOLDOWN_HOURS", "12")
+    get_settings.cache_clear()
+
+    hb = _ingest(
+        db_session,
+        type="agent.heartbeat",
+        category="agent",
+        severity="info",
+        title="hb",
+        summary="heartbeat",
+    )
+    hb.received_at = datetime.now(timezone.utc) - timedelta(hours=2)
+    db_session.flush()
+
+    trigger = _ingest(
+        db_session,
+        type="ssh.login.success",
+        severity="info",
+        title="ok",
+        summary="login",
+    )
+    problem, created = maybe_create_problem(db_session, trigger)
+    assert created is True
+
+    from app.services.problem_rules import resolve_host_silence_problems
+
+    resolve_host_silence_problems(db_session, hb.host_id)
+    db_session.refresh(problem)
+    assert problem.status == "resolved"
+    assert problem.resolved_by == "auto"
+
+    trigger2 = _ingest(
+        db_session,
+        type="ssh.login.success",
+        severity="info",
+        title="ok2",
+        summary="login2",
+    )
+    problem2, created2 = maybe_create_problem(db_session, trigger2)
+    assert created2 is True
+    assert problem2 is not None
+    assert problem2.status == "open"
+    assert problem2.id != problem.id