feat: declare all three roles, and refuse QPKG writes deliberately

A QNAP is a NAS, a hypervisor and a Linux host. It can now say so, because role
bases in napalm-device-types v1.0 declare their methods without implementing
them:

    class QnapQtsDriver(StorageDriver, HypervisorDriver, LinuxDriver):

device_class comes from the first base, so DEVICE_CLASS is gone. The get_services
forwarder is gone with it — nothing shadows LinuxDriver's version any more — and
so is the TestMroForwarding class that guarded the collisions.

Removing the shadowing exposed something the shadowing had been hiding by
accident. This driver never implemented package management; StorageDriver's stub
for install_package covered LinuxDriver's working one, so calling it raised and
looked correct. It was a coincidence, not a decision: without the stub the call
falls through to LinuxDriver, which would run apt or dnf against a NAS that has
neither. QTS uses QPKG.

get_packages, install_package and uninstall_package are therefore overridden
here to refuse with a reason, until the device harvest supplies real QPKG
parsing. See netork#114.

napalm_qnap_qts/qnap_qts.py

@@ -24,7 +24,12 @@ from __future__ import annotations
 import re
 from typing import Any
 
-from napalm_device_types import FingerprintRule, PortSpec, StorageDriver
+from napalm_device_types import (
+    FingerprintRule,
+    HypervisorDriver,
+    PortSpec,
+    StorageDriver,
+)
 from napalm_linux.linux import LinuxDriver
 
 #: QNAP Systems' IANA enterprise number. Used by discovery to recognise a NAS
@@ -42,27 +47,22 @@ _DOCKER_GLOBS = (
 _VERSION_RE = re.compile(r"(\d+)\.")
 
 
-class QnapQtsDriver(StorageDriver, LinuxDriver):
+class QnapQtsDriver(StorageDriver, HypervisorDriver, LinuxDriver):
     """NAPALM driver for QNAP NAS systems running QTS.
 
-    **Inheritance order matters.** ``StorageDriver`` precedes ``LinuxDriver`` in
-    the MRO, so its ``NotImplementedError`` stubs shadow LinuxDriver's working
-    implementations wherever the names collide — ``get_services``,
-    ``get_packages`` and ``install_package``. Each collision is resolved
-    explicitly below rather than left to the MRO; see ``TestMroForwarding``.
+    Declares all three roles it fills. The role bases carry no implementations,
+    so listing them alongside ``LinuxDriver`` costs nothing and shadows nothing;
+    what the driver can actually do is whatever it implements below.
 
-    NAS services are exposed as ``get_storage_services()``, not
-    ``get_services()``, because netOrk's poller reads the former for the storage
-    snapshot and the latter for the OS service list. Same convention as
-    napalm-openmediavault.
+    NAS services are ``get_storage_services()``; the OS service list inherited
+    from ``LinuxDriver`` stays ``get_services()``. Two names because they are two
+    different things with different return shapes, not because they collided.
     """
 
+    # A QNAP is three things at once, and the order says which one leads:
+    # storage first, so netOrk shows it as a NAS. Nothing has to restate that
+    # -- device_class is read from this line.
     TYPE_LABEL = "Storage"
-    # Declared outright: the driver inherits LinuxDriver for the OS surface, so
-    # netOrk's issubclass chain would reach OSDriver first and classify a QNAP
-    # as "linux", hiding its Storage tab. VMs and containers stay visible
-    # through capability introspection, not through this key.
-    DEVICE_CLASS = "storage"
     VENDOR = "QNAP"
     DRIVER_NAME = "qnap_qts"
     driver_name = "qnap_qts"
@@ -143,15 +143,22 @@ class QnapQtsDriver(StorageDriver, LinuxDriver):
         """Override LinuxDriver's hook: docker is not on PATH under QTS."""
         return getattr(self, "_docker_path", None) or "docker"
 
-    # ── MRO collision resolution ──────────────────────────────────────────────
+    # ── QPKG, not apt ─────────────────────────────────────────────────────────
     #
-    # StorageDriver comes first in the MRO and its stubs would otherwise win.
+    # QTS is Linux, so LinuxDriver's package methods are in the MRO and would
+    # run happily -- against a package manager QTS does not have. They used to
+    # be shadowed by StorageDriver's stubs, which made a QNAP refuse them by
+    # accident. Now that role bases implement nothing, the refusal has to be
+    # deliberate. QPKG parsing lands with the device harvest; until then,
+    # refusing is the only honest answer.
 
-    def get_services(self) -> Any:
-        """OS services, not NAS services — this is what netOrk's poller reads.
+    def get_packages(self) -> Any:
+        raise NotImplementedError(
+            "QTS uses QPKG, not a Linux package manager; QPKG parsing is not implemented yet"
+        )
 
-        Forwarded explicitly past ``StorageDriver.get_services``, which shadows
-        it and returns a different shape (dict of NAS services vs. list of OS
-        services).
-        """
-        return LinuxDriver.get_services(self)
+    def install_package(self, name: str, version: str = "") -> None:
+        raise NotImplementedError("QPKG install is not implemented yet")
+
+    def uninstall_package(self, name: str) -> None:
+        raise NotImplementedError("QPKG removal is not implemented yet")