Implement phone number normalization and access control for Telegram users

- Added functionality to normalize phone numbers for comparison, ensuring only digits are stored and checked.
- Updated configuration to include optional phone number allowlists for users and admins in the environment settings.
- Enhanced authentication logic to allow access based on normalized phone numbers, in addition to usernames.
- Introduced new helper functions for parsing and validating phone numbers, improving code organization and maintainability.
- Added unit tests to validate phone normalization and access control based on phone numbers.

.env.example

@@ -7,6 +7,10 @@ HTTP_PORT=8080
 ALLOWED_USERNAMES=username1,username2
 ADMIN_USERNAMES=admin1,admin2
 
+# Optional: allow by phone (user sets phone via /set_phone in bot). Comma-separated; normalized to digits for comparison.
+# ALLOWED_PHONES=79001234567,79007654321
+# ADMIN_PHONES=79001111111
+
 # Dev only: set to 1 to allow calendar without Telegram initData (insecure; do not use in production).
 # MINI_APP_SKIP_AUTH=1