feat: VM provisioning, and reboot_host on ESXi

create_vm_from_cloud_init takes the same qcow2/raw cloud images netOrk
offers for Proxmox. ESXi can neither boot nor download them, so the
driver does both: download with checksum check and one retry, convert
with qemu-img to a streamOptimized VMDK (cached by URL), import through
a minimal OVF descriptor over NFC, pin requested MACs, grow the disk,
and attach a NoCloud seed ISO placed next to the VM's files. NoCloud
rather than guestinfo because it needs nothing in the guest; the
user-data installs open-vm-tools, which the driver declares as its
guest agent. A failure after the import removes the VM again.

Placement is a pure decision over inventory rows: a connected host
outside maintenance mode that sees the datastore and every port group,
with the resource pool and VM folder found by walking up to the
datacenter -- one path for a standalone host and for a vCenter.

Two faults vcsim surfaced and the tests now pin: a chunked upload body
next to a Content-Length is refused with 500, so the disk goes up as a
sized file object that also reports lease progress; and a device edit
replaces the device as sent, so disk and NIC edits start from the live
objects, backing included (vcsim panicked on a disk without one).

destroy_vm, get_vm_status, get_network_targets (port groups with their
fixed VLAN) and get_image_storages complete the contract.

reboot_host on ESXi uses RebootHost_Task and refuses outside
maintenance mode: force=True would cut power to running VMs.

Tested against vcsim in ESXi and vCenter mode, end to end.

tests/test_actions.py

@@ -132,3 +132,21 @@ class TestSnapshots:
     def test_unknown_snapshot(self, driver, vm0):
         with pytest.raises(ValueError, match="no snapshot"):
             driver.rollback_vm_snapshot(vm0["name"], "nope")
+
+
+class TestRebootHost:
+    def test_esxi_in_maintenance_mode_is_rebooted(self, driver, esxi_host):
+        esxi_host["runtime.inMaintenanceMode"] = True
+        driver.reboot_host()
+        driver.mo.RebootHost_Task.assert_called_once_with(force=False)
+
+    def test_refused_outside_maintenance_mode(self, driver):
+        """force=True would power off running VMs without asking them."""
+        with pytest.raises(RuntimeError, match="maintenance mode"):
+            driver.reboot_host()
+        driver.mo.RebootHost_Task.assert_not_called()
+
+    def test_a_vcenter_cannot_reboot_itself(self):
+        from napalm_vmware import VmwareVcenterDriver
+
+        assert not hasattr(VmwareVcenterDriver, "reboot_host")