feat: onboarding without authentication

[tiankii]

Onboarding flow / login and signup experience redesign

This pull request introduces a complete update of the onboarding experience, a redesign of the login flow, a new modal logic for account upgrade prompts.

Screens redesigned or added in this feature

• Initial Screen (Create/Login)
• Login Method Selection Screen
• Welcome Level 1
• Email Benefits
• Email Confirmed
• Lightning Benefits
• Set Lightning Address
• Lightning Confirmed
• Support
• Upgrade Account Modal

These pages create a guided and progressive onboarding experience, highlighting account benefits depending on the chosen login method.

Updated login experience

• The initial screen for creating an account or logging in has been visually and structurally improved.
• The login method selection screen now shows all login options (Telegram, SMS, WhatsApp, Email) as interactive buttons with a refreshed layout.
• Dropdowns have been removed to improve accessibility and clarity.

Upgrade modal logic

A modal prompting account upgrade is now shown under the following conditions:

• On the first session if the account balance is greater than or equal to $125 USD
• On the second session, regardless of balance

The modal is displayed only once per session condition and is tracked locally via account metadata.

Additionally, on Level 0 accounts, the upgrade modal is triggered when the user attempts to generate an on-chain invoice from the Receive screen. In this case:

• The on-chain invoice button is disabled
• The modal is shown instead to encourage the upgrade

Multi-account support

The multi-account switching feature has been unlocked and no longer depends on the beta feature flag. It is now available for all users by default.

Technical improvements

• A new local GraphQL field accountMetadata was introduced to store session count and modal display tracking per account.
• A reusable hook encapsulates the modal trigger logic and manages the session metadata update.
• The header component was refactored for reusability across screens.
• Balance data is now reused from existing queries to avoid redundant GraphQL requests.