Expose image studio flow and related admin controls

Bundle the current backend and web changes into one publishable snapshot
from the server worktree so the remote mirror reflects the deployed source.

Constraint: Push the existing mixed worktree from /docker/new-api/src without reshaping files
Rejected: Split into feature-specific commits | current worktree is already a single undifferentiated snapshot
Confidence: medium
Scope-risk: moderate
Directive: Split future feature work before deployment to preserve clearer history
Tested: git status inspection; git diff --stat review
Not-tested: build, lint, unit tests, integration tests

controller/user.go

@@ -475,6 +475,12 @@ func generateDefaultSidebarConfig(userRole int) string {
 		"personal": true,
 	}
 
+	// 其他功能区域 - 所有用户都可以访问
+	defaultConfig["other"] = map[string]interface{}{
+		"enabled":      true,
+		"image_studio": true,
+	}
+
 	// 管理员区域 - 根据角色决定
 	if userRole == common.RoleAdminUser {
 		// 管理员可以访问管理员区域，但不能访问系统设置