fix(lifecycle): preserve normal owner shutdown reasons

[icostan]

Description

Jido.Scheduler.Job and Jido.Sensor.Runtime monitor an owner process and stop when it exits, but both wrapped every reason as {:owner_down, reason}. A clean owner shutdown therefore produced an exit reason OTP classifies as abnormal:

• every sensor and cron job logged a GenServer terminating crash report on the normal shutdown path (Jido.AgentServer.SensorLifecycle passes owner_pid: self(), so each sensor monitors the agent server);
• a :transient child would be restarted after its owner was already gone.

This mirrors :normal, :shutdown and {:shutdown, term} as-is and keeps wrapping anything else.

The runtime already had this exact classification in two other places — AgentServer.normal_cron_exit?/1 and Lifecycle.Keyed.clean_shutdown?/1 — so the fix would have made four copies. All four now route through a single Jido.Util.clean_exit_reason?/1.

Notes:

• No caller depends on the old shape (grep owner_down lib/ returns only the definitions). Abnormal exits still yield {:owner_down, reason}.
• Sensors implementing terminate/2 now receive the owner's own reason instead of {:owner_down, _}. @callback terminate(reason :: term(), ...) documents no shape, so this is not a contract break, and it makes standard OTP reason matching work in user sensors. Documented in a new Owner Monitoring section of the Sensor.Runtime moduledoc.
• Scheduler.Job now logs the owner exit at debug, for parity with Sensor.Runtime — a clean owner exit otherwise leaves no trace at all.

Type of Change

• Bug fix (non-breaking change fixing an issue)
• New feature (non-breaking change adding functionality)
• Breaking change (fix or feature causing existing functionality to change)
• Documentation update

Breaking Changes

None. The only observable change on the abnormal path is unchanged; on the clean path the exit reason becomes the owner's own reason rather than a wrapper.

Testing

• Tests pass (mix test) — 2283 passed, 187 excluded
• Quality checks pass (mix quality) — format, --warnings-as-errors, credo, dialyzer (0 errors)

Each preserved reason is its own test rather than a loop, so one failing reason cannot mask the others. Verified by reverting the fix locally: all six preserves … tests fail, and the two wraps an abnormal owner exit regression guards still pass.

Checklist

• My code follows the project's style guidelines
• I have updated the documentation accordingly
• I have added tests that prove my fix/feature works
• All new and existing tests pass
• My commits follow conventional commit format
• I have NOT edited CHANGELOG.md (it is auto-generated by git_ops)

Related Issues

N/A

🤖 Generated with Claude Code

https://claude.ai/code/session_011SvMs4VNrCVzWi6RNo4Xrv

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