Adds message_type + typed_payload (JSON) to MeshMessage so the UI can
render invoice/alert/coordinate/tx/lightning messages as structured
cards in both directions instead of showing raw wire bytes on the
Sent side. RPC handlers now route through send_typed_wire /
send_channel_typed_wire which transmit the binary envelope directly
(no utf8_lossy corruption) and record a rich Sent MeshMessage.
Also: store_message deduplicates echo-back doubles (20-msg lookback,
30s window), from_name is plumbed through the federation Incoming
path, and peer_dest_prefix / send_raw_payload are factored out of
send_message.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
865dccf29f