Identica: Credential provider

This update focuses on authentication reliability for mixed premium and credential setups.

Premium authentication now works consistently in both seamless and interactive flows, and fallback authentication preserves the correct provider context and result messages.

What's Changed

Fixes

• Premium: allow premium authentication to complete correctly in seamless mode
• Engine: preserve provider subject when switching to fallback providers
• Engine: keep provider-specific fallback denial results instead of showing a generic authentication failure

Full Changelog: https://github.com/whereareiam/Identica/compare/2.2.0...2.2.1