fix(optimize): drop risky Bluetooth reset, spare LaunchAgents on unmounted volumes

opt_bluetooth_reset killed bluetoothd, which disconnects HID and audio
devices; the in-use guards never covered every case and a manual restart
is rarely worth that risk. Remove the task, its has_bluetooth_hid_connected
helper, the catalog and whitelist entries, the dispatch case, and its tests.

opt_launch_agents_cleanup flagged a LaunchAgent as broken whenever its
Program path did not exist. That misfired on two safe cases: bare names
(node, python3) that resolve via PATH at launch time, and absolute paths
on a /Volumes/<disk> that is simply unplugged. Restrict "broken" to an
absolute path that is missing while its volume is mounted.