feat: M3 edit + single-step re-run — input versioning, human-modified audit, staged re-run (v0.20.0) (#161)

QA: REJECT@6ed639d (CTO rebase header P1) -> APPROVE@6727e07 (qa-reviews/prautoblogger/2026-06-12-6727e07.md)
CPO guardrails 1-5 verified hard-AC. CEO conditional greenlight 2026-06-12 in chat (QA-APPROVE condition met).

Agent-Session: cto-m3-merge-20260612

includes/admin/class-board-page.php

@@ -152,6 +152,7 @@ class PRAutoBlogger_Board_Page {
 					'edit'         => __( 'Edit', 'prautoblogger' ),
 					'viewLog'      => __( 'View Log', 'prautoblogger' ),
 					'pollError'    => __( 'Board update failed — retrying.', 'prautoblogger' ),
+					'humanModified' => __( 'Human-modified', 'prautoblogger' ),
 				),
 			)
 		);