feat(lite): lite wallet foundation (inherited working-tree state)

Preserve the previously-uncommitted lite wallet implementation and related dev WIP
under version control:
- src/wallet/ lite services: client bridge, bridge runtime, connection, lifecycle,
  sync, gateway, result parsers, state mapper, artifact contract/resolver, refresh
  services, UI adapters, wallet_backend/capabilities. (Includes two small M1 fixes:
  lifecycle walletReady now parses the response; default chain name -> "main".)
- src/chat/ chat protocol; tests/fixtures/ (lite + hushchat); tools/hushchat_fixture_check.cpp;
  scripts/build-lite-backend-artifact.sh.
- Pre-existing modified app_network/security/wizard, network_refresh_service, sidebar,
  mining_tab, bootstrap dialog, and version headers captured as-is.

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

src/ui/windows/bootstrap_download_dialog.h

@@ -29,6 +29,7 @@ namespace ui {
 class BootstrapDownloadDialog {
 public:
     static void show(App* app) {
+        if (!app || !app->supportsFullNodeLifecycleActions()) return;
         s_open = true;
         s_app = app;
         s_state = State::Confirm;
@@ -285,6 +286,7 @@ private:
 
     // ---- Shared: kick off download ----
     static void startDownload(const std::string& url) {
+        if (!s_app || !s_app->supportsFullNodeLifecycleActions()) return;
         s_wasDaemonRunning = s_app->stopDaemonForBootstrap();
         s_app->setBootstrapDownloading(true);
         s_bootstrap = std::make_unique<util::Bootstrap>();