feat: add simple jwt middleware and update oauth handlers

backend/internal/storage/models.go

@@ -17,3 +17,11 @@ type PostCreate struct {
 	Title   string `json:"title"`
 	Content string `json:"content"`
 }
+
+type User struct {
+	ID          int    `db:"id"`
+	Email       string `db:"email"`
+	GithubID    string `db:"github_id"`
+	GithubLogin string `db:"github_login"`
+	AvatarURL   string `db:"avatar_url"`
+}