feat(wallet): confirm before stopping an adopted node to switch wallets

When switching wallets, the node the app would restart may be one this session
ADOPTED — a dragonxd already running at launch (left up by "keep node running",
or started by the user). Rather than stopping it silently (or the old dead-code
"stop any external dragonxd first" refusal), show a "Stop the running node?"
confirmation first; switching then stops it (RPC stop + wait for the port to
fully free) and relaunches on the selected wallet.

- switchToWallet(walletFile, stopDaemonConfirmed=false): when the node is adopted
  (externalDaemonDetected) and not yet confirmed, defer to the dialog and return.
- renderSwitchStopDaemonDialog(): BlurFloat overlay (house style) with a warning
  header; confirm re-enters switchToWallet(w, true); cancel/X aborts, node keeps
  running. Owned nodes (started this session) still restart silently.
- i18n (EN + 8 languages, additive) + CJK subset rebuild; modal-switch-stopnode
  sweep surface for visual review.

Gate/re-entrancy adversarially verified (no state leak; owned switches ungated;
prompt reappears on a reverted switch; dead-daemon-before-confirm handled).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/app_sweep.cpp

@@ -376,6 +376,9 @@ void App::buildSweepCatalog()
     add("modal-antivirus", ui::NavPage::Mining,
         [](App& a) { a.pending_antivirus_dialog_ = true; },
         [](App& a) { a.pending_antivirus_dialog_ = false; });
+    add("modal-switch-stopnode", ui::NavPage::Settings,
+        [](App& a) { a.pending_switch_wallet_file_ = "wallet-savings.dat"; a.show_switch_stop_daemon_confirm_ = true; },
+        [](App& a) { a.show_switch_stop_daemon_confirm_ = false; a.pending_switch_wallet_file_.clear(); });
     // Wave-2 fund/secret dialogs (setup never fires the async RPC — no button is clicked).
     add("modal-shield", ui::NavPage::Send,
         [](App&) { ui::ShieldDialog::showShieldCoinbase(); },