- Replace interface{} with any in sendDeactivationRequest method signature in es2_helpers.go
- Add plugin_service_test.go with setupPluginTest helper using in-memory SQLite and gorm.AutoMigrate
- Add TestPluginService_List with test cases for all/enabled/disabled/by-type filtering and no matches
- Add TestPluginService_Install with tests for successful install, duplicate prevention, and missing fields