feat(console): add an "App" toggle to show/hide [app] log lines

The console mixed RPC traces, daemon output, and the wallet's own "[app] ..."
log lines with no way to hide the latter. Add an "App" checkbox alongside the
existing Daemon/Errors/RPC toggles. Since [app] lines share COLOR_INFO with
other info text, the filter matches them by their "[app] " prefix rather than by
color. Default on; unit test + i18n added.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/ui/windows/console_tab.h

@@ -73,6 +73,9 @@ public:
     // Show app RPC calls made through RPCClient (method/source only)
     static bool s_rpc_trace_enabled;
 
+    // Show "[app] ..." wallet log lines
+    static bool s_app_messages_enabled;
+
     /// Refresh console text colors for current theme (call after theme switch)
     static void refreshColors();