fix(orchestrator): stop auditor alert-spawn rotation — ack as auditor on dispatch

The auditor respawned every ~3 min on the same stale rework alerts.

Root cause: _dispatch_audit_work's alert path fetched the SYSTEM-wide
"not fully acked" view (list_system_notifications), but the auditor is
read-only (no ack verb) and auditor_triage never acks — so once an alert
existed the CEO was the only party who could clear it, and the CEO hadn't
acked. The per-alert cooldown (PR #499) only paced a rotation through the
N un-acked alerts; it was a damper, not a fix.

Fix: fetch the auditor's OWN pending-ack view (GET /notifications authed
as the auditor -> list_for_agent, which filters acked_by for the auditor)
and ack the alert as the auditor on dispatch. Each alert is now a
one-shot, DB-persistent: the next tick cannot respawn on an alert the
auditor already observed — even one the CEO hasn't acked. Authed as the
auditor (not the system identity) so the route selects the per-recipient
view; HTTP rather than DB-direct so it shares the orchestrator's loop in
prod and stays loop-safe in the e2e harness (which runs _dispatch_audit_work
in its own asyncio.run loop, away from the app's DB engine).

e2e now asserts the alert is in acked_by for the auditor after dispatch —
the rotation-stopper itself, not just the spawn.

tests/unit/runtime/test_scheduled_audit_trigger.py

@@ -26,10 +26,13 @@ def orch() -> AgentOrchestrator:
 async def _run_dispatch(
     orch: AgentOrchestrator, *, tasks: list[dict] | None = None
 ) -> MagicMock:
-    """Run _dispatch_audit_work with notifications empty and return the spawn mock."""
+    """Run _dispatch_audit_work with no unobserved alerts and return the spawn mock."""
     client = MagicMock()
     with (
-        patch.object(orch, "_fetch_notifications", new=AsyncMock(return_value=[])),
+        patch.object(
+            orch, "_next_unobserved_audit_alert", new=AsyncMock(return_value=None)
+        ),
+        patch.object(orch, "_ack_alert_as_auditor", new=AsyncMock()),
         patch.object(orch, "_fetch_tasks", new=AsyncMock(return_value=tasks or [])),
         patch.object(orch, "_is_agent_active", return_value=False),
         patch.object(orch, "spawn_agent", new=AsyncMock()) as spawn_mock,
@@ -111,7 +114,10 @@ async def test_breaker_skips_when_auditor_active(orch: AgentOrchestrator) -> Non
     with (
         patch.object(settings, "audit_interval_seconds", 21600),
         patch("roboco.runtime.orchestrator.datetime", wraps=datetime) as dt_mock,
-        patch.object(orch, "_fetch_notifications", new=AsyncMock(return_value=[])),
+        patch.object(
+            orch, "_next_unobserved_audit_alert", new=AsyncMock(return_value=None)
+        ),
+        patch.object(orch, "_ack_alert_as_auditor", new=AsyncMock()),
         patch.object(orch, "_fetch_tasks", new=AsyncMock(return_value=[])),
         patch.object(orch, "_is_agent_active", return_value=True),
         patch.object(orch, "spawn_agent", new=AsyncMock()) as spawn_mock,
@@ -129,8 +135,7 @@ async def test_reactive_alert_stamps_last_spawn_and_blocks_scheduled(
     """A reactive alert spawn records _last_audit_spawn_at and returns early."""
     client = MagicMock()
     alert = {
-        "id": "a1",
-        "to_agents": ["auditor"],
+        "id": "11111111-1111-1111-1111-111111111111",
         "subject": "Coverage gap",
         "body": "Test",
     }
@@ -138,7 +143,10 @@ async def test_reactive_alert_stamps_last_spawn_and_blocks_scheduled(
     with (
         patch.object(settings, "audit_interval_seconds", 21600),
         patch("roboco.runtime.orchestrator.datetime", wraps=datetime) as dt_mock,
-        patch.object(orch, "_fetch_notifications", new=AsyncMock(return_value=[alert])),
+        patch.object(
+            orch, "_next_unobserved_audit_alert", new=AsyncMock(return_value=alert)
+        ),
+        patch.object(orch, "_ack_alert_as_auditor", new=AsyncMock()),
         patch.object(orch, "_fetch_tasks", new=AsyncMock(return_value=[])),
         patch.object(orch, "_is_agent_active", return_value=False),
         patch.object(orch, "spawn_agent", new=AsyncMock()) as spawn_mock,
@@ -149,6 +157,43 @@ async def test_reactive_alert_stamps_last_spawn_and_blocks_scheduled(
     assert orch._last_audit_spawn_at == now
 
 
+@pytest.mark.anyio
+async def test_reactive_alert_acks_so_it_cannot_rotate(
+    orch: AgentOrchestrator,
+) -> None:
+    """The alert is acked as the auditor on dispatch, so the next tick —
+    which would otherwise re-fetch the same stale alert and respawn — finds
+    no unobserved alert and falls through to the scheduled path (blocked by
+    the just-stamped _last_audit_spawn_at). This is the rotation-stopper.
+    """
+    client = MagicMock()
+    alert_id = "22222222-2222-2222-2222-222222222222"
+    alert = {
+        "id": alert_id,
+        "subject": "Rework alert",
+        "body": "Task entered needs_revision",
+    }
+    now = datetime.now(UTC)
+    ack_mock = AsyncMock()
+    fetch_mock = AsyncMock(side_effect=[alert, None])
+    with (
+        patch.object(settings, "audit_interval_seconds", 21600),
+        patch("roboco.runtime.orchestrator.datetime", wraps=datetime) as dt_mock,
+        patch.object(orch, "_next_unobserved_audit_alert", new=fetch_mock),
+        patch.object(orch, "_ack_alert_as_auditor", new=ack_mock),
+        patch.object(orch, "_fetch_tasks", new=AsyncMock(return_value=[])),
+        patch.object(orch, "_is_agent_active", return_value=False),
+        patch.object(orch, "spawn_agent", new=AsyncMock()) as spawn_mock,
+    ):
+        dt_mock.now.return_value = now
+        await orch._dispatch_audit_work(client)  # tick 1: alert -> spawn + ack
+        await orch._dispatch_audit_work(client)  # tick 2: no alert -> scheduled
+    assert spawn_mock.await_count == 1  # not respawned on tick 2
+    assert ack_mock.await_count == 1
+    # acked as the auditor saw it: (client, alert_id)
+    assert ack_mock.await_args.args[1] == alert_id
+
+
 @pytest.mark.anyio
 async def test_cooldown_zero_disables_scheduled_sweeps(orch: AgentOrchestrator) -> None:
     """ROBOCO_AUDIT_INTERVAL_SECONDS=0 disables scheduled sweeps entirely."""