fix: properly implement JWT user object in middleware

- Update JWT middleware to set complete user object in context
- Parse UUID correctly and convert to pgtype.UUID format
- Add missing imports for uuid and pgx/v5/pgtype
- Fix type conversion from UUID string to byte array
- Ensure compatibility with database.Users struct

Resolves authentication issues for library and user endpoints

cmd/server/main.go

@@ -11,6 +11,8 @@ import (
 
 	"github.com/go-playground/validator/v10"
 	"github.com/golang-jwt/jwt/v5"
+	"github.com/google/uuid"
+	"github.com/jackc/pgx/v5/pgtype"
 	"github.com/labstack/echo-jwt/v4"
 	"github.com/labstack/echo/v4"
 	"github.com/labstack/echo/v4/middleware"
@@ -64,6 +66,20 @@ func main() {
 			c.Set("user_role", claims["user_role"])
 			c.Set("user_email", claims["user_email"])
 			c.Set("user_username", claims["user_username"])
+			// Parse UUID from string claims
+			userIDStr, _ := claims["user_id"].(string)
+			userUUID, err := uuid.Parse(userIDStr)
+			if err != nil {
+				c.JSON(http.StatusBadRequest, map[string]string{"error": "invalid user ID in token"})
+				return
+			}
+
+			c.Set("user", database.Users{
+				ID:       pgtype.UUID{Bytes: [16]byte(userUUID), Valid: true},
+				Email:    claims["user_email"].(string),
+				Username: claims["user_username"].(string),
+				Role:     claims["user_role"].(string),
+			})
 		},
 	})