[ML 0.1/UI.04] - Connect Message List Screen with Legacy Data

🎯 The objective

Connect MessageListScreen to the existing legacy data sources and business logic, bridging the new Compose-based UI layer with the current Message List state management, data providers, and interaction handlers while maintaining clear module boundaries.

🎒 Resources

• Depends on #10573

🦮 Rules of the Road

🟢 In Scope

• Wiring Compose UI to legacy data sources (no mock/placeholder data)
• Pull-to-refresh triggering legacy refresh mechanism
• Footer button ("lazy load") wiring
• Swipe actions triggering legacy handlers
• Message item click delegation to existing navigation/interaction logic
• State mapping layer (legacy model -> UI model) in :feature:mail:message:list:internal
• Unified folder support
• Account indicator visibility

🔴 Out of Scope

• Infinite scrolling (tracked separately)
• Refactoring or rewriting legacy business logic
• Architectural changes to the legacy data layer
• UI redesign or structural changes to the screen or list items
• Performance optimizations beyond what is required for safe integration

🚧 Technical and/or Business Requirements

• Must use adapter/mapping layers over direct coupling between Compose and legacy classes
• Maintain strict module boundaries: :feature:mail:message:list:api / :feature:mail:message:list:internal
• Legacy dependencies must remain encapsulated and not exposed through the public API
• No business logic migrated or rewritten - only wiring and adaptation
• Any temporary interoperability code should be clearly documented for future cleanup

📋 Sub-tickets

• #10774
• #10775
• #10776
• #10777
• #10778
• #10779
• #10780
• #10781
• #10782
• #10783
• #10784

Start at MessageListScreen and review dependency #10573, then trace the legacy data sources and handlers within :feature:mail:message:list:api and :feature:mail:message:list:internal. Use the listed sub-tickets to identify remaining wiring, and consider the work done when refresh, lazy loading, swipe actions, clicks, state mapping, unified folders, and account indicators work without exposing legacy classes.