fix(aihr): recover stalled media processing

backend/script/sql/aihr_knowledge_mysql8.sql

@@ -199,6 +199,7 @@ CREATE TABLE IF NOT EXISTS `aihr_knowledge_upload_item` (
   `category` varchar(100) DEFAULT '' COMMENT '目标分类',
   `space_codes_json` json DEFAULT NULL COMMENT '目标知识空间编码数组',
   `staging_path` varchar(500) NOT NULL COMMENT '暂存文件路径',
+  `source_attach_id` bigint DEFAULT NULL COMMENT '从既有附件重新解析时的附件ID',
   `status` tinyint NOT NULL DEFAULT 0 COMMENT '0待处理 1处理中 2完成 3失败',
   `error` varchar(500) DEFAULT NULL COMMENT '失败原因',
   `doc_id` varchar(80) DEFAULT NULL COMMENT '入库文档ID',
@@ -207,7 +208,8 @@ CREATE TABLE IF NOT EXISTS `aihr_knowledge_upload_item` (
   `update_time` datetime DEFAULT NULL COMMENT '更新时间',
   PRIMARY KEY (`id`),
   KEY `idx_aihr_upload_item_batch` (`tenant_id`, `batch_id`, `id`),
-  KEY `idx_aihr_upload_item_status` (`tenant_id`, `status`, `update_time`)
+  KEY `idx_aihr_upload_item_status` (`tenant_id`, `status`, `update_time`),
+  KEY `idx_aihr_upload_item_source` (`tenant_id`, `source_attach_id`, `id`)
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci COMMENT='知识库批量上传队列';
 
 CREATE TABLE IF NOT EXISTS `aihr_knowledge_space_grant` (