resolve potential thread locks in Dexie.js during high-frequency WebSocket streams

[itsVentie]

Description

With the introduction of Groups and Public Channels, rapid execution of the background dual-fetch strategy (GetMessages) coupled with incoming Supabase/PostgreSQL real-time INSERT sockets can lead to write-contention or brief rendering freezes inside the Dexie.js message vault.

Todo

• Refactor message batch ingestion routines inside the frontend storage hook to utilize database transactions (db.transaction('rw', ...)).
• Implement a brief debounce window (~50ms) for DOM re-paints when updating the active message buffer slice from IndexedDB.
• Ensure that plaintext payload processing occurs entirely in decoupled execution tracks before updating the reactive state.