Remote comms: Persistent message queue

[sirtimid]

Problem: Currently, queued messages are only in memory. If the kernel restarts during reconnection, all queued messages are lost. This can cause message loss for important operations.

Expected Behavior:

• Persist queued messages to kernel store
• Load queued messages on initNetwork startup
• Resume sending queued messages after restart
• Define message lifecycle policies (TTL, expiry, cleanup)

Implementation:

• Integrate MessageQueue with kernel store (KVStore or StoredQueue)
• Persist on enqueue (or batch periodically for performance)
• Load on initNetwork startup
• Remove from store on successful dequeue
• Add message TTL/expiry logic (e.g., drop messages older than X days)
• Clean up stale messages on startup
• Consider message ordering and duplicate handling

Acceptance Criteria:

• Queued messages persist across restarts
• Messages are loaded and resumed on startup
• Old/stale messages are cleaned up
• Performance is acceptable (batching may be needed)
• Tests verify persistence and recovery