Give a default value to projectName in Text-to-CAD Create command to allow invocation through command palette (#7061)

Give a default value to projectName

This argument is hidden since it's marked as skip, so browser users who
must now invoke the command through the command palette have no way of
setting the value. Since it is also required, the command palette fails
silently on submission (which we need to fix more broadly). This gives
it a default value so that users can submit properly.

src/lib/commandBarConfigs/applicationCommandConfig.ts

@@ -150,6 +150,7 @@ export function createApplicationCommands({
         required: (commandsContext) =>
           isDesktop() &&
           commandsContext.argumentsToSubmit.method === 'existingProject',
+        defaultValue: isDesktop() ? undefined : 'browser',
         skip: true,
         options: (_, _context) => {
           const { folders } = systemIOActor.getSnapshot().context