fix(auth): wiring Auth/Sessions, нормализация email, GetUserByID для /me, 409 на дубль, timing-guard логина

internal/api/api.go

@@ -61,6 +61,7 @@ type ProviderRegistry interface {
 type AuthStore interface {
 	RegisterUser(ctx context.Context, email, passwordHash string) (store.User, store.Project, error)
 	GetUserByEmail(ctx context.Context, email string) (store.User, error)
+	GetUserByID(ctx context.Context, userID uuid.UUID) (store.User, error)
 	GetUserProject(ctx context.Context, userID uuid.UUID) (store.Project, error)
 }