fix(agent): cache runtime receipt readback under db pool pressure

apps/api/tests/test_ai_agent_autonomous_runtime_control.py

@@ -210,6 +210,8 @@ def _assert_log_controlled_writeback_consumer(payload: dict):
 async def test_live_runtime_receipt_keeps_consumer_readback_when_trace_query_fails(
     monkeypatch,
 ):
+    runtime_control_module._clear_runtime_receipt_readback_cache()
+
     async def _fake_consumer_readback(*, project_id: str):
         assert project_id == "awoooi"
         return _log_controlled_writeback_consumer_readback()
@@ -225,9 +227,12 @@ async def test_live_runtime_receipt_keeps_consumer_readback_when_trace_query_fai
         _fake_consumer_readback,
     )
 
-    readback = (
-        await runtime_control_module.load_ai_agent_autonomous_runtime_receipt_readback()
-    )
+    try:
+        readback = (
+            await runtime_control_module.load_ai_agent_autonomous_runtime_receipt_readback()
+        )
+    finally:
+        runtime_control_module._clear_runtime_receipt_readback_cache()
 
     assert readback["db_read_status"] == "unavailable"
     assert readback["error"]["type"] == "RuntimeError"
@@ -236,6 +241,99 @@ async def test_live_runtime_receipt_keeps_consumer_readback_when_trace_query_fai
     )
 
 
+@pytest.mark.asyncio
+async def test_live_runtime_receipt_readback_uses_short_cache_to_protect_db_pool(
+    monkeypatch,
+):
+    runtime_control_module._clear_runtime_receipt_readback_cache()
+    calls = 0
+
+    async def _fake_uncached_loader(
+        *,
+        project_id: str,
+        lookback_hours: int,
+        limit: int,
+    ) -> dict:
+        nonlocal calls
+        calls += 1
+        return build_runtime_receipt_readback_from_rows(
+            project_id=project_id,
+            lookback_hours=lookback_hours,
+            db_read_status="ok",
+            service_log_count_rows=[
+                {"status": "sanitized_recent_logs", "total": calls, "recent": calls},
+            ],
+        )
+
+    monkeypatch.setattr(
+        runtime_control_module,
+        "_load_ai_agent_autonomous_runtime_receipt_readback_uncached",
+        _fake_uncached_loader,
+    )
+
+    try:
+        first = await runtime_control_module.load_ai_agent_autonomous_runtime_receipt_readback()
+        second = await runtime_control_module.load_ai_agent_autonomous_runtime_receipt_readback()
+    finally:
+        runtime_control_module._clear_runtime_receipt_readback_cache()
+
+    assert calls == 1
+    assert first["db_read_status"] == "ok"
+    assert second["db_read_status"] == "ok"
+    assert (
+        second["log_integration_taxonomy"]["rollups"]["classified_event_total"]
+        == first["log_integration_taxonomy"]["rollups"]["classified_event_total"]
+    )
+
+
+@pytest.mark.asyncio
+async def test_live_runtime_receipt_readback_does_not_cache_pool_unavailable(
+    monkeypatch,
+):
+    runtime_control_module._clear_runtime_receipt_readback_cache()
+    calls = 0
+
+    async def _fake_uncached_loader(
+        *,
+        project_id: str,
+        lookback_hours: int,
+        limit: int,
+    ) -> dict:
+        nonlocal calls
+        calls += 1
+        if calls == 1:
+            return build_runtime_receipt_readback_from_rows(
+                project_id=project_id,
+                lookback_hours=lookback_hours,
+                db_read_status="unavailable",
+                error_type="TimeoutError",
+            )
+        return build_runtime_receipt_readback_from_rows(
+            project_id=project_id,
+            lookback_hours=lookback_hours,
+            db_read_status="ok",
+            service_log_count_rows=[
+                {"status": "sanitized_recent_logs", "total": 3, "recent": 1},
+            ],
+        )
+
+    monkeypatch.setattr(
+        runtime_control_module,
+        "_load_ai_agent_autonomous_runtime_receipt_readback_uncached",
+        _fake_uncached_loader,
+    )
+
+    try:
+        first = await runtime_control_module.load_ai_agent_autonomous_runtime_receipt_readback()
+        second = await runtime_control_module.load_ai_agent_autonomous_runtime_receipt_readback()
+    finally:
+        runtime_control_module._clear_runtime_receipt_readback_cache()
+
+    assert calls == 2
+    assert first["db_read_status"] == "unavailable"
+    assert second["db_read_status"] == "ok"
+
+
 def test_runtime_control_rollups_project_consumer_dispatch_ledger_if_trace_missing():
     payload = build_ai_agent_autonomous_runtime_control()
     readback = build_runtime_receipt_readback_from_rows(