QTS is a Linux distribution, so the driver inherits the OS surface from
LinuxDriver and adds QNAP's storage, QPKG and virtualisation layers.
What is here: the class with its discovery fingerprints, per-session
detection of the QTS major version and of the QPKG-local docker and virsh
binaries, and explicit resolution of the MRO collisions that StorageDriver
creates over LinuxDriver.
What is not: the storage, QPKG and VM parsers. Those need real command
output from QTS 4 and QTS 5 hardware to be written against, which is what
tools/harvest.sh collects and tools/sanitize.py anonymises. Two tests are
marked xfail(strict) as the specification for that work.