fix: remove stale docblock above on_manual_generation() in class-executor.php

Deletes the stale 'Cron handler: runs pipeline orchestration + first article' docblock
that was left stacked above the real M4 docblock. Leaves exactly one docblock
immediately above the method (the v0.21.0 M4 description). No logic change.

Agent-Session: phase2-admin-m4-20260614

includes/class-executor.php

@@ -84,13 +84,6 @@ class PRAutoBlogger_Executor {
 		$this->poller()->on_ajax_generate_now();
 	}
 
-	/**
-	 * Cron handler: runs pipeline orchestration + first article.
-	 *
-	 * If the pipeline queues additional articles (2..N), they will fire as
-	 * chained cron events — each in its own PHP process. The lock is released
-	 * by the pipeline when the last article completes, not here.
-	 */
 	/**
 	 * Cron handler: kick off the chained-cron orchestration tick (v0.21.0, M4).
 	 *