fix：修复数据库中两个字符串的排序规则（collation）不一致问题

main/manager-api/src/main/resources/db/changelog/202506161101.sql

@@ -0,0 +1 @@
+ALTER TABLE ai_agent_plugin_mapping CONVERT TO CHARACTER SET utf8mb4;

main/manager-api/src/main/resources/db/changelog/db.changelog-master.yaml

@@ -205,3 +205,10 @@ databaseChangeLog:
         - sqlFile:
             encoding: utf8
             path: classpath:db/changelog/202506080955.sql
+  - changeSet:
+      id: 202506161101
+      author: hrz
+      changes:
+        - sqlFile:
+            encoding: utf8
+            path: classpath:db/changelog/202506161101.sql