test: add comprehensive test coverage and improve code quality

- Add new test files for auth, service, and handler modules
- Improve test organization and coverage
- Refactor code for better maintainability
- Add captcha, settings, stats, and theme handler tests
- Add auth module tests (CAS, OAuth, password, SSO, state)
- Add service layer tests for auth, export, permissions, roles
- All Go tests pass (exit code 0)
- All frontend tests pass (325 tests in 59 files)

internal/service/theme.go

@@ -21,30 +21,30 @@ func NewThemeService(themeRepo *repository.ThemeConfigRepository) *ThemeService
 
 // CreateThemeRequest 创建主题请求
 type CreateThemeRequest struct {
-	Name           string `json:"name" binding:"required"`
-	LogoURL        string `json:"logo_url"`
-	FaviconURL     string `json:"favicon_url"`
-	PrimaryColor   string `json:"primary_color"`
-	SecondaryColor string `json:"secondary_color"`
+	Name            string `json:"name" binding:"required"`
+	LogoURL         string `json:"logo_url"`
+	FaviconURL      string `json:"favicon_url"`
+	PrimaryColor    string `json:"primary_color"`
+	SecondaryColor  string `json:"secondary_color"`
 	BackgroundColor string `json:"background_color"`
-	TextColor      string `json:"text_color"`
-	CustomCSS      string `json:"custom_css"`
-	CustomJS       string `json:"custom_js"`
-	IsDefault      bool   `json:"is_default"`
+	TextColor       string `json:"text_color"`
+	CustomCSS       string `json:"custom_css"`
+	CustomJS        string `json:"custom_js"`
+	IsDefault       bool   `json:"is_default"`
 }
 
 // UpdateThemeRequest 更新主题请求
 type UpdateThemeRequest struct {
-	LogoURL        string `json:"logo_url"`
-	FaviconURL     string `json:"favicon_url"`
-	PrimaryColor   string `json:"primary_color"`
-	SecondaryColor string `json:"secondary_color"`
+	LogoURL         string `json:"logo_url"`
+	FaviconURL      string `json:"favicon_url"`
+	PrimaryColor    string `json:"primary_color"`
+	SecondaryColor  string `json:"secondary_color"`
 	BackgroundColor string `json:"background_color"`
-	TextColor      string `json:"text_color"`
-	CustomCSS      string `json:"custom_css"`
-	CustomJS       string `json:"custom_js"`
-	Enabled        *bool  `json:"enabled"`
-	IsDefault      *bool  `json:"is_default"`
+	TextColor       string `json:"text_color"`
+	CustomCSS       string `json:"custom_css"`
+	CustomJS        string `json:"custom_js"`
+	Enabled         *bool  `json:"enabled"`
+	IsDefault       *bool  `json:"is_default"`
 }
 
 // CreateTheme 创建主题
@@ -64,14 +64,14 @@ func (s *ThemeService) CreateTheme(ctx context.Context, req *CreateThemeRequest)
 		Name:            req.Name,
 		LogoURL:         req.LogoURL,
 		FaviconURL:      req.FaviconURL,
-		PrimaryColor:   req.PrimaryColor,
-		SecondaryColor: req.SecondaryColor,
+		PrimaryColor:    req.PrimaryColor,
+		SecondaryColor:  req.SecondaryColor,
 		BackgroundColor: req.BackgroundColor,
-		TextColor:      req.TextColor,
-		CustomCSS:      req.CustomCSS,
-		CustomJS:       req.CustomJS,
-		IsDefault:      req.IsDefault,
-		Enabled:        true,
+		TextColor:       req.TextColor,
+		CustomCSS:       req.CustomCSS,
+		CustomJS:        req.CustomJS,
+		IsDefault:       req.IsDefault,
+		Enabled:         true,
 	}
 
 	// 如果设置为默认，先清除其他默认