feat(M3): edit+rerun schema substrate — stage_inputs store, stale/human_modified columns, db 1.3.0

- Pipeline_Schema_Installer: run_stages gains human_modified + stale
  (stale is a COLUMN not a status: rows stay 'done' so resume code can
  never silently re-run them — CPO guardrail 3 by construction);
  run_decisions gains human_modified; new INSERT-only stage_inputs table
  (edit forks as immutable versions + idea seeds for re-run-from-here).
  All dbDelta-idempotent; PRAUTOBLOGGER_DB_VERSION 1.1.0 -> 1.3.0 (the
  constant never carried the documented 1.2.0) so the existing
  admin_init/cron self-healing migration path fires everywhere.
- Run_Stage_State split (M2 pattern, was 313 lines): pipeline write
  bodies moved verbatim to Run_Stage_Writes (public API unchanged via
  thin proxies); done() now clears stale on fresh output with a
  half-migrated-schema retry (Cost_Tracker v0.18.0 pattern); new
  item-scoped read stages_for_item(). Operator-action mutations
  (restart/mark_stale/demote_to_pending) isolated in
  Run_Stage_Rerun_State — the only code allowed to demote a done row.
- Audit_Writer::flag_decisions_human_modified() (guardrail 2 on
  run_decisions). Run_Reaper retention prunes human fork bodies (seeds
  kept). Uninstall covers the new table + rerun cron hooks.

Agent-Session: engineer-prab-m3-20260612

includes/core/class-run-reaper.php

@@ -16,8 +16,9 @@ declare(strict_types=1);
  *          ledger/state activity for 2× the expected run wall-clock are
  *          marked `failed` and their non-done stages reaped to `failed`;
  *          such runs render as "incomplete" via incomplete_runs().
- *       3. Retention — `request_json` on generation_log and stage output
+ *       3. Retention — `request_json` on generation_log, stage output
  *          payloads (`meta_json` on run_stages) are NULLed after R days;
+ *          payloads, and stage_inputs human-fork bodies (v0.20.0);
  *          R comes from the `prautoblogger_request_json_retention_days`
  *          SETTING (default constant 14; 0 = keep forever) — never a
  *          literal at the point of use.
@@ -265,6 +266,11 @@ class PRAutoBlogger_Run_Reaper {
 			$pruned += is_numeric( $result ) ? (int) $result : 0;
 		}
 
+		// v0.20.0: human edit-fork bodies ride the same retention (seed
+		// rows are kept — structural, ~1KB). A pruned fork can no longer
+		// be replayed; the dossier explains that state honestly.
+		$pruned += PRAutoBlogger_Stage_Input_Store::prune_human_bodies( $cutoff );
+
 		return $pruned;
 	}
 }