The orphan-research-row reaper (upcoming commit) needs a cheap way to
answer "which posts belong to this run_id?" when amortizing a stranded
`llm_research` row back to its siblings. Relying on the generation_log
post_id column is circular: if the pipeline died before amortize_research
ran, we'd trust the same table we're trying to repair.
- `Publisher::build_meta()` now accepts `?string $run_id` and writes
`_prautoblogger_run_id => $run_id` when non-empty. Null/empty preserves
existing null-safe legacy behaviour.
- `Publisher::create_post()` forwards the $run_id it already receives
into build_meta — one-line plumbing, no new parameters at call sites.
- `Activator::backpopulate_run_id_meta_v081()` runs once per site,
gated by `prautoblogger_migrated_run_id_meta_v081` option. Walks
`wp_prautoblogger_generation_log`, pairs (post_id, min(run_id)),
writes `_prautoblogger_run_id` on any post that doesn't already have
it. Uses `metadata_exists()` so it's a no-op on re-run.
- Activator also schedules the new daily `prautoblogger_reap_orphan_research_rows`
cron at 03:15 — 15 min after the primary generation cron — so live
pipelines have time to finish amortizing cleanly before the reaper scans.
- Deactivator unschedules the new hook alongside the existing cron hooks.
No user-visible behaviour change yet. The reaper handler ships in the
next commit; this one just ensures it will have the data + schedule it
needs when it lands.
Part of the v0.8.1 bundle (thread research-cost-reaper).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>