How can I fix Bluetooth not working after upgrading to Bluefin weekly image 43.20260106, where Bluetooth appears disabled in GNOME and `bluetoothctl list` shows no adapters, but rolling back restores functionality?

This Bluetooth regression is a known issue after recent Bluefin updates. The most common cause is incorrect permissions on /var/lib/bluetooth, which prevents the Bluetooth service from functioning properly. To resolve this, follow these steps:

Set correct permissions:
```
sudo chmod 755 /var/lib/bluetooth -R
```
Restart the Bluetooth service:
```
sudo systemctl restart bluetooth
```
Temporarily set SELinux to permissive (if applicable):
```
sudo setenforce 0
```
Unblock Bluetooth:
```
sudo rfkill unblock bluetooth
```
Restart the Bluetooth service again:
```
sudo systemctl restart bluetooth
```

After these steps, Bluetooth devices should reappear in GNOME and bluetoothctl. This fix typically survives reboots and rebasing to newer images. For more details and discussion, see this issue.

If you are using a Mac with a T2 chip, you may need a custom Bluefin image with the correct Broadcom firmware (T2-Atomic project).

If the workaround does not resolve the issue, check for error messages using journalctl -u bluetooth or dmesg | grep -i bluetooth and provide them for further diagnosis.