Initial Screen

Create the initial screen with a large "Log in via Telegram" button, plus smaller "About Us" and "Documents" buttons.

📋 Acceptance Criteria

• GIVEN the user lands on the initial screen

• WHEN they see login options

• THEN they can choose to log in or view documents/about

• GIVEN the user taps "Log in via Telegram"

• WHEN Telegram auth is successful

• THEN the user is taken to the subscription selection screen

✅ Please check the Definition of Done before moving this issue to Close.