Add POST /api/cron/jobs/{id}/run endpoint that triggers a cron job
immediately without waiting for its next scheduled fire time. The job
executes asynchronously in the background and its status can be polled
via the existing /status endpoint.
Key changes:
- Extract per-job execution logic from the inline cron tick loop into
a reusable `cron_run_job()` method on OpenFangKernel, called by both
the background scheduler and the new API endpoint
- Add `reserve_run()` on CronScheduler to pre-advance next_run for
overdue jobs before spawning manual runs, preventing duplicate
execution from the scheduler tick (only advances when next_run <= now
to avoid skipping imminent scheduled runs)
- Fix dashboard scheduler.js to call the correct cron API endpoint
instead of the legacy /api/schedules/ path
- Document all cron/scheduler endpoints in api-reference.md
Partially addresses upstream issue #634.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
