Fix bug of groups

Optimizations * Optimized the process for adding new contacts. * Optimized message delivery to offline contacts. * Optimized group management and synchronization.

# What's New ### Reliability & Sync Improvements - Added per-conversation sync freshness tracking to reduce unnecessary message reloads and improve realtime stability. - Implemented smarter reconnect behavior across realtime reconnects, page visibility changes, and network recovery events. - Conversations synced within the last 30 seconds now reuse trusted local state instead of triggering redundant server fetches. - Added app-wide reconciliation after login to ensure recent conversations and messages are immediately available after sign-in. - Implemented reconciliation deduplication with TTL-based protection to avoid excessive reload cycles during repeated logins. ### Deep Link & Contact Synchronization - Improved contact invitation consistency for deep-link onboarding flows. - Deep-link invitations now automatically establish mutual contact relationships without requiring manual refreshes. - Added duplicate-prevention safeguards across client and database layers for contact synchronization integrity. - Added automated tests covering deep-link mutual contact creation and idempotent acceptance flows. - Added user feedback and localized confirmations for successful contact synchronization events. ### Diagnostics & Internal Instrumentation - Added new debug instrumentation for read receipt flushing reliability during rapid tab close scenarios. - Added runtime metrics and logging tools for contact synchronization flows and reconnect diagnostics. - Added developer debug toggles for realtime inspection of sync, flush, and reconciliation behavior. ### General Improvements - Improved cache trust validation and hydration performance across the application. - Expanded localization coverage for new sync and invitation-related user feedback. - Various stability improvements, performance optimizations, and internal reliability enhancements.

What’s New in This Version * Improved reliability for read receipts when the app is closed or tabs are switched rapidly. * Added advanced diagnostics and debug metrics for message delivery and read-state synchronization. * Deep-link invitations now create mutual contacts automatically and consistently across devices. * Added protections against duplicate contact creation during concurrent sync operations. * New automated validation tests for deep-link contact synchronization and acceptance flows. * Added user feedback notifications when contacts are added or already connected. * Expanded localization coverage for contact sync feedback across all supported languages. * Improved internal synchronization stability and database integrity handling for contact relationships. * General performance, reliability, and stability improvements across the messaging experience.