feat: restore learning feedback and knowledge capabilities

backend/script/sql/aihr_knowledge_mysql8.sql

@@ -5,7 +5,7 @@ CREATE TABLE IF NOT EXISTS `aihr_knowledge_info` (
   `id` bigint NOT NULL AUTO_INCREMENT COMMENT '主键',
   `tenant_id` varchar(20) DEFAULT '000000' COMMENT '租户编号',
   `name` varchar(100) NOT NULL COMMENT '知识库名称',
-  `code` varchar(100) NOT NULL COMMENT '租户内稳定空间编码',
+  `code` varchar(100) DEFAULT NULL COMMENT '租户内稳定空间编码；平台迁移会回填 legacy 编码并改为必填',
   `space_type` varchar(30) NOT NULL DEFAULT 'BUSINESS' COMMENT 'PUBLIC/BUSINESS/MANAGEMENT/EXTERNAL',
   `sensitivity_level` varchar(30) NOT NULL DEFAULT 'INTERNAL' COMMENT 'PUBLIC/INTERNAL/CONFIDENTIAL',
   `status` varchar(20) NOT NULL DEFAULT 'ACTIVE' COMMENT 'DRAFT/ACTIVE/DISABLED',
@@ -230,3 +230,17 @@ CREATE TABLE IF NOT EXISTS `aihr_knowledge_query_log` (
   KEY `idx_aihr_query_tenant_app` (`tenant_id`, `app_id`, `create_time`),
   KEY `idx_aihr_query_status` (`tenant_id`, `status`, `create_time`)
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci COMMENT='知识问答最小化审计日志';
+
+CREATE TABLE IF NOT EXISTS `aihr_knowledge_admin_audit` (
+  `id` bigint NOT NULL AUTO_INCREMENT COMMENT '主键',
+  `tenant_id` varchar(20) NOT NULL COMMENT '租户编号',
+  `operator_id` bigint DEFAULT NULL COMMENT '操作人',
+  `action` varchar(50) NOT NULL COMMENT '操作动作',
+  `object_type` varchar(30) NOT NULL COMMENT 'SPACE/GRANT/APP/APP_SPACE/TOKEN',
+  `object_id` bigint DEFAULT NULL COMMENT '对象ID',
+  `before_summary` varchar(1000) DEFAULT NULL COMMENT '变更前摘要',
+  `after_summary` varchar(1000) DEFAULT NULL COMMENT '变更后摘要',
+  `create_time` datetime NOT NULL COMMENT '操作时间',
+  PRIMARY KEY (`id`),
+  KEY `idx_aihr_admin_audit_tenant` (`tenant_id`, `create_time`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci COMMENT='知识平台管理变更审计';