[GFI] Add Authy Two-Factor Authentication

[roncodes]

Description:
Introduce Authy (or similar) as an additional two-factor authentication option.

Tasks:

• Integrate Authy API for device-based 2FA.
• Replace or augment existing SMS/email 2FA with proper provider implementation.
• Update settings page to allow users to enable/disable Authy 2FA.
• Ensure secure 2FA challenge on login.

Acceptance Criteria:

• Users can register Authy for their account.
• Login flow includes 2FA challenge when enabled.
• Existing 2FA via SMS/email still works as fallback.
• All 2FA actions are logged securely.

References:

• Related models: User, Setting.
• Review current 2FA logic for compatibility.