feat(admin): add comprehensive admin management system

- Add admin handlers and services for users, posts, comments, groups, and dashboard
- Implement role permission management with ability to view and update permissions
- Add database seeding for roles and Casbin permission policies
- Upgrade Casbin from v2 to v3 with GORM adapter for persistent policy storage
- Add admin-specific repository methods with filtering and pagination
- Register new admin API routes under /api/v1/admin/*

internal/wire/casbin.go

@@ -8,7 +8,8 @@ import (
 	"carrot_bbs/internal/repository"
 	"carrot_bbs/internal/service"
 
-	"github.com/casbin/casbin/v2"
+	"github.com/casbin/casbin/v3"
+	gormadapter "github.com/casbin/gorm-adapter/v3"
 	"github.com/google/wire"
 	"gorm.io/gorm"
 )
@@ -22,19 +23,24 @@ var CasbinSet = wire.NewSet(
 
 // ProvideCasbinEnforcer 提供 Casbin Enforcer
 func ProvideCasbinEnforcer(cfg *config.Config, db *gorm.DB) *casbin.Enforcer {
-	// 创建 Casbin Enforcer
-	// 注意：这里使用文件适配器作为示例，实际使用时需要替换为数据库适配器
-	enforcer, err := casbin.NewEnforcer(cfg.Casbin.ModelPath)
+	// 创建 GORM 适配器，连接数据库
+	adapter, err := gormadapter.NewAdapterByDB(db)
+	if err != nil {
+		log.Fatalf("Failed to create Casbin GORM adapter: %v", err)
+	}
+
+	// 创建 Casbin Enforcer，使用数据库适配器
+	enforcer, err := casbin.NewEnforcer(cfg.Casbin.ModelPath, adapter)
 	if err != nil {
 		log.Fatalf("Failed to create Casbin enforcer: %v", err)
 	}
 
-	// 加载策略
+	// 从数据库加载策略
 	if err := enforcer.LoadPolicy(); err != nil {
 		log.Printf("[WARNING] Failed to load Casbin policy: %v", err)
 	}
 
-	log.Println("[Wire] Initialized Casbin enforcer")
+	log.Println("[Wire] Initialized Casbin enforcer with GORM adapter")
 	return enforcer
 }