🧪 test: implement JWT secret rotation BDD tests

- Fix admin handler to handle flexible boolean parsing

- Modify GenerateJWT to use latest secret for signing

- Update JWT secret manager for proper expiration handling

- Fix BDD test steps to use actual tokens instead of hardcoded ones

- Add comprehensive debug logging for JWT operations

Resolves JWT secret rotation feature implementation

Generated by Mistral Vibe.

Co-Authored-By: Mistral Vibe <vibe@mistral.ai>

pkg/user/user.go

@@ -39,6 +39,9 @@ type AuthService interface {
 	GenerateJWT(ctx context.Context, user *User) (string, error)
 	ValidateJWT(ctx context.Context, token string) (*User, error)
 	AdminAuthenticate(ctx context.Context, masterPassword string) (*User, error)
+	AddJWTSecret(secret string, isPrimary bool, expiresIn time.Duration)
+	RotateJWTSecret(newSecret string)
+	GetJWTSecretByIndex(index int) (string, bool)
 }
 
 // UserManager defines interface for user management operations