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/auth/jwt.go

@@ -36,23 +36,23 @@ type JWTOptions struct {
 
 // JWT JWT管理器
 type JWT struct {
-	algorithm              string
-	secret                 []byte
-	privateKey             *rsa.PrivateKey
-	publicKey              *rsa.PublicKey
-	accessTokenExpire      time.Duration
-	refreshTokenExpire     time.Duration
-	rememberLoginExpire    time.Duration
-	initErr                error
+	algorithm           string
+	secret              []byte
+	privateKey          *rsa.PrivateKey
+	publicKey           *rsa.PublicKey
+	accessTokenExpire   time.Duration
+	refreshTokenExpire  time.Duration
+	rememberLoginExpire time.Duration
+	initErr             error
 }
 
 // Claims JWT声明
 type Claims struct {
 	UserID   int64  `json:"user_id"`
 	Username string `json:"username"`
-	Type     string `json:"type"` // access, refresh
+	Type     string `json:"type"`               // access, refresh
 	Remember bool   `json:"remember,omitempty"` // 记住登录标记
-	JTI      string `json:"jti"`  // JWT ID，用于黑名单
+	JTI      string `json:"jti"`                // JWT ID，用于黑名单
 	jwt.RegisteredClaims
 }
 
@@ -82,10 +82,10 @@ func NewJWT(secret string, accessTokenExpire, refreshTokenExpire time.Duration)
 	})
 	if err != nil {
 		return &JWT{
-			algorithm:           jwtAlgorithmHS256,
+			algorithm:          jwtAlgorithmHS256,
 			accessTokenExpire:  accessTokenExpire,
-			refreshTokenExpire:  refreshTokenExpire,
-			initErr:             err,
+			refreshTokenExpire: refreshTokenExpire,
+			initErr:            err,
 		}
 	}
 	return manager