feat(monitor): 死信中文提示与成功/取消自动退信

internal/platform/postgres/queue_sql.go

@@ -64,6 +64,16 @@ WHERE id = $1
   AND state = 'running'
 `
 
+// retireOpenFailuresSQL keeps the dead-letter lane honest: once the job
+// itself succeeded, its terminal-attempt projection is no longer waiting on
+// a human (a later automatic retry recovered it).
+const retireOpenFailuresSQL = `
+UPDATE job_failures
+SET state = 'requeued', resolved_at = $2, resolution_actor_ref = 'system:queue',
+    resolution_reason = '任务后续重试成功'
+WHERE job_id = $1 AND state = 'open'
+`
+
 const heartbeatJobSQL = `
 UPDATE jobs
 SET lease_until = $4,