feat(cron): support structured script payloads

[JackALaing]

Summary

• Teach cron pre-run scripts to return a structured JSON object that can replace {{ var }} prompt placeholders via template_vars.
• Allow structured payloads to prepend explicit context with prepend_context, while preserving the existing raw stdout context behavior for non-JSON output.
• Track cleanup_paths from structured payloads and remove those temporary script artifacts after the cron job finishes.

Test Plan

• python -m pytest tests/cron/test_scheduler.py -q
• python -m py_compile cron/scheduler.py

Platforms Tested

• macOS / Darwin arm64, Python 3.13.13

Related / competing PRs

Searches run for cron structured payload, script payload, scheduled job script, cron script, and deliver found no PR that fully supersedes this structured payload contract.

Adjacent cron script/delivery PRs:

• PR #19709 merged no_agent script-only cron jobs; this PR keeps the LLM-backed pre-run script path and only shapes script output before prompt execution.
• PR #20354, PR #19810, PR #20323, and PR #21397 touch cron script invocation details such as arguments, environment, failure status, and workdir. They are complementary to this PR's stdout payload contract.
• PR #21438 and PR #21441 adjust Discord/Slack threading and delivery mirroring. This PR intentionally avoids delivery routing, Discord thread semantics, media attachments, and mirror history.

Notes/Risks

• Cross-platform impact: this touches cron script output handling and cleanup of files named by script payloads. Cleanup uses pathlib.Path and only unlinks paths that currently exist as files.
• Structured payload parsing only applies when the script stdout is a JSON object. Non-JSON stdout continues to be prepended as the existing script-output context block.

[teknium1]

Thanks for the focused cron extension. The structured-output feature is not present on current main, so this is worth salvaging, but it needs updates for the current scheduler flow.

Problems

• cron/scheduler.py:891 records cleanup_paths only while building the prompt. Current main exits on a successful wakeAgent=false result at cron/scheduler.py:2632-2645, before prompt construction, so those artifacts are never registered or removed.
• Current main marks ordinary script stdout as injected data at cron/scheduler.py:2177-2200; that selects the runtime-data scanner at cron/scheduler.py:2412-2425. The structured branches need the same treatment, otherwise command-shaped feed data in prepend_context can be blocked despite the established contract in tests/cron/test_cron_prompt_injection_skill.py:359-395.

Suggested changes

• Register cleanup metadata before the wake-gate return and add a wakeAgent:false cleanup regression test.
• Carry the injected-data state through structured payload handling, with tests for command-shaped context and genuine injection directives.
• Document the JSON payload fields in website/docs/user-guide/features/cron.md.

Automated hermes-sweeper review.

[teknium1]

run_job performs the wakeAgent=false return before it calls _build_job_prompt on current main (cron/scheduler.py:2632-2645). A payload that includes cleanup_paths and suppresses the agent never reaches this assignment, so the final cleanup has nothing to unlink. Parse/register cleanup metadata before that gate and add a wake-gated regression test.

[teknium1]

When salvaging onto current main, structured prepend_context must set the same has_injected_data state used for ordinary script stdout (cron/scheduler.py:2177-2200). Without it, the assembled prompt takes the strict scanner path instead of the runtime-data path covered by tests/cron/test_cron_prompt_injection_skill.py:359-395.