Fix Connect button hanging on Bluetooth retries

[oneydef]

Summary

• Shorten Bluetooth connect retries and add a fast path when A2DP is already up, so Connect no longer freezes the GUI for minutes.
• Unlock header controls with a soft timeout if a background connect stalls, and fix PyGObject shutdown chaining on exit.

Test plan

• Launch eara gui with earbuds already connected — Connect should finish almost immediately and show BT on / protocol ok
• Power Bluetooth off, then press Connect — adapter powers on and buds reconnect without the UI staying disabled forever
• Force a slow/failing connect — after ~90s buttons unlock again with a timeout message
• Close the app — no Gio.Application.shutdown() TypeError in the journal

Made with Cursor