로그인 페이지 및 기능 구현

backend/internal/handler/auth_handler.go

@@ -97,6 +97,11 @@ func (h *AuthHandler) CheckEmail(c *fiber.Ctx) error {
 		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "Invalid request"})
 	}
 
+	// Email Format Validation
+	if !strings.Contains(req.Email, "@") || !strings.Contains(req.Email, ".") {
+		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "Invalid email format"})
+	}
+
 	if h.DescopeClient == nil {
 		return c.Status(fiber.StatusServiceUnavailable).JSON(fiber.Map{"error": "Identity provider unavailable"})
 	}
@@ -366,7 +371,7 @@ func (h *AuthHandler) Signup(c *fiber.Ctx) error {
 		slog.Error("[Signup] Failed to set password", "error", err)
 		// Rollback? Delete user?
 		h.DescopeClient.Management.User().Delete(context.Background(), req.Email)
-		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "Failed to set password"})
+		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": fmt.Sprintf("Failed to set password: %v", err)})
 	}
 
 	// 4. Cleanup Redis