feat: enhance v2 components and entity join functionality

- Add entity join controller/routes enhancements
- Improve table management and category value services
- Update v2 table list, card display, search widget components
- Improve split panel layout responsiveness

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/types/tableCategoryValue.ts

@@ -15,6 +15,7 @@ export interface TableCategoryValue {
   // 계층 구조
   parentValueId?: number;
   depth?: number;
+  path?: string;
   
   // 추가 정보
   description?: string;

frontend/types/v2-components.ts

@@ -137,6 +137,7 @@ export type V2SelectSource = "static" | "code" | "db" | "api" | "entity" | "cate
 export interface SelectOption {
   value: string;
   label: string;
+  displayLabel?: string;
 }
 
 /**