feat(testutils): add CreateTestServiceWithDuration fixture

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

backend/testutils/fixtures/fixtures.go

@@ -71,6 +71,20 @@ func CreateTestService(q db.Querier) (string, error) {
 	return serviceID, nil
 }
 
+func CreateTestServiceWithDuration(q db.Querier, durationMinutes int) (string, error) {
+	ctx := context.Background()
+	var serviceID string
+	err := q.QueryRow(ctx, `
+		INSERT INTO services (name, description, price, duration_minutes, is_active, minimum_age_required)
+		VALUES ($1, $2, $3, $4, $5, $6)
+		RETURNING id
+	`, fmt.Sprintf("Test Service %dmin", durationMinutes), "A test service for unit tests", 50.00, durationMinutes, true, 16).Scan(&serviceID)
+	if err != nil {
+		return "", fmt.Errorf("failed to create service: %w", err)
+	}
+	return serviceID, nil
+}
+
 // CreateTestServiceWithPatchTest creates a service and a patch test that links to it
 // Returns serviceID, patchTestID
 func CreateTestServiceWithPatchTest(q db.Querier) (string, string, error) {