fix(settings): open the settings window from Cmd-comma and links

[datlechin]

Why

• On main since test: replace sleeps with barriers and isolate shared test state #3421, Settings never opens: Cmd-comma, the menu item and tablepro://settings links do nothing. 5 UI flows fail on it.
• test: replace sleeps with barriers and isolate shared test state #3421 replaced SettingsWindowController's init() with init(registryClient: RegistryClient = .shared). present still calls SettingsWindowController(), which now resolves to the inherited init() and builds a controller with no window.

Change

• An explicit init() delegates to init(registryClient: .shared); the registry parameter has no default, so the call can't fall through again.

Verified

• New SettingsWindowTitleTests.testTheInitializerPresentUsesBuildsTheSettingsWindow builds the controller the way present does and fails on main (no window). Reproduced locally: with the settings URL, main's build opens no window at all.