Sharingan v1.7.3

fix(launch): 1.7.3 — never block launch on the widget-snapshot write

A wedged containermanagerd hangs open() on the group container forever;
the snapshot write ran on the main thread inside
applicationDidFinishLaunching, freezing the app with no windows and no
menu bar icon (observed live via sample: main thread parked in
Data.write → open). Writes now go through a serial utility queue;
publishFinal stays synchronous but routed through the same queue so
ordering holds.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>