nanokvm: address review feedback and remove dead serial/SSH code

- Extract NanoKVMDriverBase to deduplicate client management across
  NanoKVMVideo and NanoKVMHID (~30 lines of copy-paste removed)
- Remove NanoKVMSerial placeholder class and all SSH/serial config
  (enable_serial, ssh_username, ssh_password, ssh_port)
- Fix stream re-auth bug: keep send_stream context open during retry
  so the retry can still write to the stream
- Replace asyncio.create_task with anyio.create_task_group for
  consistency with project conventions
- Apply @with_reauth decorator directly on NanoKVM composite methods
  instead of fragile inner-function pattern; delegate _get_client and
  _reset_client to video child driver
- Fix mount_image unmount logic: pass None explicitly for unmount
  instead of confusing `mount_file or None` expression
- Add pytest-asyncio to dev dependencies (needed for asyncio_mode=auto)
- Remove jumpstarter-driver-pyserial dependency (only needed for serial)
- Add get_images to API docs :members: list
- Remove serial/SSH references from README and documentation

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: Ambient Code Bot

python/packages/jumpstarter-driver-nanokvm/README.md

@@ -41,50 +41,28 @@ export:
       password: "admin"      # Default NanoKVM web interface password
 ```
 
-### Advanced Configuration
-
-```yaml
-export:
-  nanokvm:
-    type: jumpstarter_driver_nanokvm.driver.NanoKVM
-    config:
-      host: "192.168.1.100"
-      username: "admin"
-      password: "your-password"
-      # Optional: SSH access for serial console (future feature)
-      enable_serial: false
-      ssh_username: "root"
-      ssh_password: "root"
-      ssh_port: 22
-```
-
 ### Config Parameters
 
 | Parameter      | Description                                | Type  | Required | Default |
 | -------------- | ------------------------------------------ | ----- | -------- | ------- |
 | host           | NanoKVM hostname or IP address             | str   | yes      |         |
 | username       | Web interface username                     | str   | no       | "admin" |
 | password       | Web interface password                     | str   | no       | "admin" |
-| enable_serial  | Enable serial console access via SSH       | bool  | no       | false   |
-| ssh_username   | SSH username for serial console            | str   | no       | "root"  |
-| ssh_password   | SSH password for serial console            | str   | no       | "root"  |
-| ssh_port       | SSH port for serial console                | int   | no       | 22      |
 
 ## Architecture
 
-The NanoKVM driver is a composite driver that provides three main interfaces:
+The NanoKVM driver is a composite driver that provides two main interfaces:
 
 1. **video**: Video streaming and snapshot capture
 2. **hid**: Keyboard and mouse HID control
-3. **serial**: Serial console access (optional, future feature)
 
 ## API Reference
 
 ### NanoKVMClient
 
 ```{eval-rst}
 .. autoclass:: jumpstarter_driver_nanokvm.client.NanoKVMClient()
-    :members: get_info, reboot, mount_image, download_image, get_mounted_image, get_cdrom_status, is_image_download_enabled, get_image_download_status
+    :members: get_info, reboot, mount_image, download_image, get_mounted_image, get_cdrom_status, is_image_download_enabled, get_image_download_status, get_images
 ```
 
 ### NanoKVMVideoClient

python/packages/jumpstarter-driver-nanokvm/examples/exporter.yaml

@@ -12,8 +12,3 @@ export:
       host: "192.168.1.110"  # or IP address like "192.168.1.100"
       username: "admin"
       password: "admin"
-      # Optional: Enable serial console access via SSH
-      # enable_serial: true
-      # ssh_username: "root"
-      # ssh_password: "root"
-      # ssh_port: 22

python/packages/jumpstarter-driver-nanokvm/jumpstarter_driver_nanokvm/__init__.py

@@ -3,11 +3,8 @@
 This package provides support for NanoKVM devices, including:
 - Video streaming and snapshot capture
 - Keyboard and mouse HID control
-- Serial console access (optional)
 """
 
 from .driver import NanoKVM, NanoKVMHID, NanoKVMVideo
 
 __all__ = ["NanoKVM", "NanoKVMVideo", "NanoKVMHID"]
-
-

python/packages/jumpstarter-driver-nanokvm/jumpstarter_driver_nanokvm/client.py

@@ -269,7 +269,6 @@ class NanoKVMClient(CompositeClient):
     This composite client provides access to all NanoKVM functionality:
     - video: Video streaming and snapshots
     - hid: Keyboard and mouse control
-    - serial: Serial console access (if enabled)
 
     Example::