feat: 更新后端skill服务

- 更新 skill_handler.go handler层
- 更新 skill.go model层
- 更新 skill_repo.go repository层
- 更新 skill_service.go service层
- 更新 main.go 入口文件

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/cmd/api/main.go

@@ -121,19 +121,15 @@ func ensureAdminWorkspace() {
 		}
 	}
 
-	// 创建 admin 工作空间
-	workspacePath := filepath.Join(projectRoot, "account", "admin")
-	if err := os.MkdirAll(workspacePath, 0755); err != nil {
-		log.Printf("Warning: failed to create admin workspace: %v", err)
-		return
+	// 创建 skills 目录结构: core/agents/skills/{system,user}
+	skillsRoot := filepath.Join(projectRoot, "core", "agents", "skills")
+	for _, dir := range []string{"system", "user"} {
+		if err := os.MkdirAll(filepath.Join(skillsRoot, dir), 0755); err != nil {
+			log.Printf("Warning: failed to create skills directory %s: %v", dir, err)
+		}
 	}
 
-	// 创建子目录: skills(技能), scripts(脚本), sandbox(沙盒), files(文件), temp(临时)
-	for _, dir := range []string{"skills", "scripts", "sandbox", "files", "temp"} {
-		os.MkdirAll(filepath.Join(workspacePath, dir), 0755)
-	}
-
-	log.Printf("Admin workspace created at: %s", workspacePath)
+	log.Printf("Skills workspace created at: %s", skillsRoot)
 }
 
 func main() {
@@ -240,6 +236,11 @@ func main() {
 
 	// 使用GORM Migrator添加缺失的列
 	migrator := db.Migrator()
+
+	// Skill 表迁移
+	if !migrator.HasColumn(&model.Skill{}, "created_by") {
+		migrator.AddColumn(&model.Skill{}, "created_by")
+	}
 	if !migrator.HasColumn(&model.Tool{}, "security_level") {
 		migrator.AddColumn(&model.Tool{}, "security_level")
 	}
@@ -306,12 +307,12 @@ func main() {
 		log.Println("Default tools initialized")
 	}
 
-	// 4.3 初始化 skills
-	if err := skillService.InitSkills(); err != nil {
-		log.Printf("Warning: Failed to init skills: %v", err)
-	} else {
-		log.Println("Skills initialized")
-	}
+	// 4.3 初始化 skills（已禁用自动加载，如需启用请调用 /skill/sync 接口）
+	// if err := skillService.InitSkills(); err != nil {
+	// 	log.Printf("Warning: Failed to init skills: %v", err)
+	// } else {
+	// 	log.Println("Skills initialized")
+	// }
 
 	// 6. 初始化 Handler
 	dbHandler := handler.NewDatabaseHandler(dbService)