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_output_model.cpp

@@ -21,6 +21,8 @@ bool consoleLinePassesFilter(const std::string& lineText,
 {
     if (!filter.daemonMessagesEnabled && lineColor == filter.daemonColor) return false;
     if (!filter.rpcTraceEnabled && lineColor == filter.rpcTraceColor) return false;
+    // "[app] ..." lines share COLOR_INFO with other info text, so match them by prefix.
+    if (!filter.appMessagesEnabled && lineText.rfind("[app] ", 0) == 0) return false;
     if (filter.errorsOnly && lineColor != filter.errorColor) return false;
     if (!filter.text.empty()) {
         std::string needle = lowerCopy(filter.text);