feat: enhance staff management and payment gateway features

- Fix national code handling in staff creation and updates to support Persian digits.
- Update ClinicStaff entity to allow longer national codes (up to 15 characters).
- Implement support for clinic secretaries in SecretaryController, allowing creation without a doctor UUID.
- Add a new endpoint to retrieve doctors associated with a clinic for secretary management.
- Improve appointment management by ensuring doctors are selectable even when no appointments exist.
- Extend PatientController to allow secretaries to create patient records if they have the appropriate permissions.
- Introduce a PriceInput component for better price formatting in forms, supporting Persian digits.
- Add a MockGateway for testing payment processes without real transactions.
- Enhance SMS settings management with an approval flow for post-visit text messages, including new fields for pending text and status.
- Update migrations to reflect changes in database schema for national codes and SMS settings.

docs/api/staff.md

@@ -57,7 +57,7 @@
 | phone | string | ❌ |
 | job_title | string | ❌ |
 | address | string | ❌ |
-| national_code | string(10) | ❌ |
+| national_code | string(15) — ارقام فارسی به لاتین تبدیل می‌شوند | ❌ |
 
 **Response 201:**
 ```json