fix(cron): dual-case keys when loading jobs.json

jobs.json hand-edits and asdict-style snake_case for schedule intervals and
runHistory crashed or silently disabled cron. Deserialize via Cron* from_store_dict
and shared get_camel_snake (also used by local triggers).

nanobot/triggers/local_types.py

@@ -6,15 +6,11 @@ from dataclasses import dataclass, field
 from pathlib import Path
 from typing import Any, Literal
 
+from nanobot.utils.dict_keys import get_camel_snake as _get
+
 TriggerStatus = Literal["ok", "error"]
 
 
-def _get(data: dict[str, Any], camel: str, snake: str, default: Any = None) -> Any:
-    if camel in data:
-        return data[camel]
-    return data.get(snake, default)
-
-
 @dataclass
 class TriggerRunRecord:
     """A single local trigger delivery record."""