feat(cron): add script field for pre-run data collection (#5082)

Add an optional 'script' parameter to cron jobs that references a Python
script. The script runs before each agent turn, and its stdout is injected
into the prompt as context. This enables stateful monitoring — the script
handles data collection and change detection, the LLM analyzes and reports.

- cron/jobs.py: add script field to create_job(), stored in job dict
- cron/scheduler.py: add _run_job_script() executor with timeout handling,
  inject script output/errors into _build_job_prompt()
- tools/cronjob_tools.py: add script to tool schema, create/update handlers,
  _format_job display
- hermes_cli/cron.py: add --script to create/edit, display in list/edit output
- hermes_cli/main.py: add --script argparse for cron create/edit subcommands
- tests/cron/test_cron_script.py: 20 tests covering job CRUD, script
  execution, path resolution, error handling, prompt injection, tool API

Script paths can be absolute or relative (resolved against ~/.hermes/scripts/).
Scripts run with a 120s timeout. Failures are injected as error context so
the LLM can report the problem. Empty string clears an attached script.

hermes_cli/main.py

@@ -4381,6 +4381,7 @@ For more help on a command:
     cron_create.add_argument("--deliver", help="Delivery target: origin, local, telegram, discord, signal, or platform:chat_id")
     cron_create.add_argument("--repeat", type=int, help="Optional repeat count")
     cron_create.add_argument("--skill", dest="skills", action="append", help="Attach a skill. Repeat to add multiple skills.")
+    cron_create.add_argument("--script", help="Path to a Python script whose stdout is injected into the prompt each run")
 
     # cron edit
     cron_edit = cron_subparsers.add_parser("edit", help="Edit an existing scheduled job")
@@ -4394,6 +4395,7 @@ For more help on a command:
     cron_edit.add_argument("--add-skill", dest="add_skills", action="append", help="Append a skill without replacing the existing list. Repeatable.")
     cron_edit.add_argument("--remove-skill", dest="remove_skills", action="append", help="Remove a specific attached skill. Repeatable.")
     cron_edit.add_argument("--clear-skills", action="store_true", help="Remove all attached skills from the job")
+    cron_edit.add_argument("--script", help="Path to a Python script whose stdout is injected into the prompt each run. Pass empty string to clear.")
 
     # lifecycle actions
     cron_pause = cron_subparsers.add_parser("pause", help="Pause a scheduled job")