fix(triggers): coerce null ms fields when loading local triggers

Explicit JSON null for runAtMs/createdAtMs raised TypeError and could
quarantine triggers.json. Treat null/blank like a missing key (0).

nanobot/triggers/local_types.py

@@ -11,6 +11,13 @@ from nanobot.utils.dict_keys import get_camel_snake as _get
 TriggerStatus = Literal["ok", "error"]
 
 
+def _ms_int(value: Any, default: int = 0) -> int:
+    """Coerce JSON numerics to int; treat null/blank like a missing key."""
+    if value is None or value == "":
+        return default
+    return int(value)
+
+
 @dataclass
 class TriggerRunRecord:
     """A single local trigger delivery record."""
@@ -22,7 +29,7 @@ class TriggerRunRecord:
     @classmethod
     def from_dict(cls, data: dict[str, Any]) -> "TriggerRunRecord":
         return cls(
-            run_at_ms=int(_get(data, "runAtMs", "run_at_ms", 0)),
+            run_at_ms=_ms_int(_get(data, "runAtMs", "run_at_ms", 0)),
             status=str(data.get("status") or "error"),  # type: ignore[arg-type]
             error=data.get("error"),
         )
@@ -70,8 +77,8 @@ class LocalTrigger:
             session_key=str(_get(data, "sessionKey", "session_key", "")),
             sender_id=str(_get(data, "senderId", "sender_id", "trigger") or "trigger"),
             origin_metadata=dict(_get(data, "originMetadata", "origin_metadata", {}) or {}),
-            created_at_ms=int(_get(data, "createdAtMs", "created_at_ms", 0)),
-            updated_at_ms=int(_get(data, "updatedAtMs", "updated_at_ms", 0)),
+            created_at_ms=_ms_int(_get(data, "createdAtMs", "created_at_ms", 0)),
+            updated_at_ms=_ms_int(_get(data, "updatedAtMs", "updated_at_ms", 0)),
             last_run_at_ms=_get(data, "lastRunAtMs", "last_run_at_ms"),
             last_status=_get(data, "lastStatus", "last_status"),  # type: ignore[arg-type]
             last_error=_get(data, "lastError", "last_error"),
@@ -120,8 +127,8 @@ class TriggerDelivery:
             id=str(data["id"]),
             trigger_id=str(_get(data, "triggerId", "trigger_id", "")),
             content=str(data.get("content") or ""),
-            created_at_ms=int(_get(data, "createdAtMs", "created_at_ms", 0)),
-            attempts=int(data.get("attempts", 0)),
+            created_at_ms=_ms_int(_get(data, "createdAtMs", "created_at_ms", 0)),
+            attempts=_ms_int(data.get("attempts", 0)),
             last_error=data.get("lastError") or data.get("last_error"),
             path=path,
         )

tests/triggers/test_local_triggers.py

@@ -490,3 +490,29 @@ async def test_local_trigger_queue_recovers_processing_delivery_on_start(
     assert submitted[0].content == "Review PR #4591"
     assert submitted[0].metadata["_local_trigger"]["trigger_id"] == trigger.id
     assert restarted.claim_deliveries() == []
+
+
+def test_local_trigger_from_dict_accepts_null_run_at_ms() -> None:
+    from nanobot.triggers.local_types import LocalTrigger, TriggerDelivery
+
+    trigger = LocalTrigger.from_dict(
+        {
+            "id": "t1",
+            "name": "n",
+            "enabled": True,
+            "channel": "websocket",
+            "chatId": "c1",
+            "sessionKey": "websocket:c1",
+            "runHistory": [{"runAtMs": None, "status": "ok"}],
+            "createdAtMs": None,
+            "updatedAtMs": None,
+        }
+    )
+    assert trigger.run_history[0].run_at_ms == 0
+    assert trigger.created_at_ms == 0
+    assert trigger.updated_at_ms == 0
+
+    delivery = TriggerDelivery.from_dict(
+        {"id": "d1", "triggerId": "t1", "content": "hi", "createdAtMs": None}
+    )
+    assert delivery.created_at_ms == 0