feat(mesh): rich typed Sent records and echo dedup

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>

core/archipelago/src/api/handler/node_message.rs

@@ -17,6 +17,7 @@ impl ApiHandler {
         }
         let incoming: Incoming = serde_json::from_slice(&body).unwrap_or(Incoming {
             from_pubkey: None,
+            from_name: None,
             message: None,
             signature: None,
             encrypted: false,