apply.sh now inspects B2RcloneRemote.__dict__ before patching. If TrueNAS
has shipped get_restic_config natively, it sets the kill switch, unmounts
overlays, and logs a clear instruction to run uninstall.sh.
Also: drop all conditional 'if read-only' language — overlay is always
mounted unconditionally since /usr is always immutable on TrueNAS SCALE.
README updated with auto-disable behaviour and revised native-support table.