feat(wallet): Lightning gets the arrival screen; copy buttons unified

- lnd.createinvoice now returns r_hash_hex; new lnd.invoicestatus RPC
  looks the invoice up (SETTLED + amt_paid_sat). E2E-verified on this
  box: real invoice minted, status polls settled:false until paid.
- Receive modal: Lightning polls settlement every 3s and flips to the
  on-chain-style success view — straight to the green check + amount
  (no broadcast step; settlement is final). Raw bolt11 text removed:
  QR + CopyButton only. State fully reset per open/close.
- CopyButton is now the wallet's only copy affordance: the ark-address
  and ecash-token holdouts swapped in, their ad-hoc handlers deleted.

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

core/archipelago/src/api/rpc/dispatcher.rs

@@ -133,6 +133,7 @@ impl RpcHandler {
             "lnd.sendcoins" => self.handle_lnd_sendcoins(params).await,
             "lnd.estimatefee" => self.handle_lnd_estimatefee(params).await,
             "lnd.createinvoice" => self.handle_lnd_createinvoice(params).await,
+            "lnd.invoicestatus" => self.handle_lnd_invoicestatus(params).await,
             "lnd.payinvoice" => self.handle_lnd_payinvoice(params).await,
             "lnd.paymentstatus" => self.handle_lnd_paymentstatus(params).await,
             "lnd.create-psbt" => self.handle_lnd_create_psbt(params).await,