feat(wallet): LND wedge watchdog + Fedi send rail + token QRs + Auto hidden

- LND watchdog: framework-pt's LND sat wedged 14h (RPC up, server never
  ready, channels inactive) with nothing noticing. 15 consecutive bad
  minutes now bounce the container automatically (30min cooldown) —
  silent multi-hour Lightning outages become self-healed blips.
- Send modal: Auto tab hidden; Ecash splits into Cashu and Fedi (new
  wallet.fedimint-send RPC wrapping the existing spend_from_any); both
  rails render the generated token as a scannable QR alongside the
  copyable text.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

core/archipelago/src/server.rs

@@ -106,6 +106,9 @@ impl Server {
         // seconds of hitting the mempool (works whenever LND is up; retries
         // forever otherwise). User req 2026-07-22.
         crate::api::rpc::lnd::spawn_lnd_tx_watcher(state_manager.clone());
+        // LND wedge watchdog — self-heal the silent "RPC up, server never
+        // ready" state instead of waiting for a human (100%-uptime req).
+        crate::api::rpc::lnd::spawn_lnd_health_watchdog();
 
         // Retry Tor address in background — Tor may not be ready at startup
         if data.server_info.tor_address.is_none() {