[cli] llama-stack-client models register passed to server as a string (needs to be dict)

[mattf]

System Info

llama stack 0.1.9
incidental: ollama provider w/ ollama 0.6.3

Information

• The official example scripts
• My own modified scripts

🐛 Describe the bug

$ uv run llama-stack-client models register all-MiniLM-L6-v2 --provider-model-id all-minilm:latest --metadata '{"field": "value"}'

╭────────────────────────────────────────────────────────────────────────────────────────────────╮
│ Failed to register model                                                                       │
│                                                                                                │
│ Error Type: BadRequestError                                                                    │
│ Details: Error code: 400 - {'error': {'detail': {'errors': [{'loc': ['body', 'metadata'],      │
│ 'msg': 'Input should be a valid dictionary', 'type': 'dict_type'}]}}}                          │
╰────────────────────────────────────────────────────────────────────────────────────────────────╯

the --metadata param is a string, see https://github.com/meta-llama/llama-stack-client-python/blob/7e00b784ee859aa04aa11955e3888e5167331dfe/src/llama_stack_client/lib/cli/models/models.py#L109

the server expects a dict, see https://github.com/meta-llama/llama-stack/blob/19f504e9e267759c489af287049d479176730d27/docs/_static/llama-stack-spec.yaml#L4855

Error logs

15:03:23.223 [START] /v1/models
Traceback (most recent call last):
  File ".../lib64/python3.10/site-packages/starlette/_exception_handler.py", line 42, in wrapped_app
    await app(scope, receive, sender)
  File ".../lib64/python3.10/site-packages/starlette/routing.py", line 73, in app
    response = await f(request)
  File ".../lib64/python3.10/site-packages/fastapi/routing.py", line 346, in app
    raise validation_error
fastapi.exceptions.RequestValidationError: [{'type': 'dict_type', 'loc': ('body', 'metadata'), 'msg': 'Input should be a valid dictionary', 'input': '{"field": "value"}'}]
INFO:     ::1:60438 - "POST /v1/models HTTP/1.1" 400 Bad Request

Expected behavior

cli to convert metadata to type expected by server