feat(lnd): capture aezeed at wallet init + encrypted backup + reveal UI

- aezeed words are now captured at BOTH wallet-init paths and stored
  encrypted (Argon2 + ChaCha20-Poly1305, per-node wallet secret) at
  identity/lnd_aezeed.enc; ack marker cleared when a wallet is recreated
- lnd.init-wallet-from-seed was posting seed_entropy to /v1/initwallet,
  which is a GenSeed field — the wallet was never actually derived from
  the master seed; now GenSeed(entropy) → InitWallet(words)
- new RPCs: lnd.seed-backup-status / lnd.seed-reveal (password + 2FA
  gated, same as seed.reveal via shared verify_reveal_auth) /
  lnd.seed-backup-ack
- LND app detail page: Lightning-seed card with first-launch backup
  prompt, tap-to-reveal modal, 'I've backed it up' acknowledgment

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

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

@@ -135,6 +135,9 @@ impl RpcHandler {
             "lnd.connect-info" => self.handle_lnd_connect_info().await,
             "lnd.export-channel-backup" => self.handle_lnd_export_channel_backup().await,
             "lnd.init-wallet-from-seed" => self.handle_lnd_init_wallet_from_seed(params).await,
+            "lnd.seed-backup-status" => self.handle_lnd_seed_backup_status().await,
+            "lnd.seed-reveal" => self.handle_lnd_seed_reveal(params).await,
+            "lnd.seed-backup-ack" => self.handle_lnd_seed_backup_ack().await,
 
             // Multi-identity management
             "identity.list" => self.handle_identity_list(params).await,