Use of `SKChatCompletionAdapter` reliably fails with "'MockValSer'
object cannot be converted to 'SchemaSerializer'"; can repro with this
example:
https://microsoft.github.io/autogen/stable/user-guide/core-user-guide/components/model-clients.html#semantic-kernel-adapter

This appears to be related to
pydantic/pydantic#7713 - commit uses
workaround from
pydantic/pydantic#7713 (comment)

## Why are these changes needed?

This unblocks use of the Semantic Kernel integration by addressing the
above-referenced error, enabling the integration to perform as expected.

## Related issue number

N/A, see pydantic/pydantic#7713 for context,
though.

## Checks

- [X] I've included any doc changes needed for
<https://microsoft.github.io/autogen/>. See
<https://github.com/microsoft/autogen/blob/main/CONTRIBUTING.md> to
build and test documentation locally.
 - None needed, internal only change.
- [ ] I've added tests (if relevant) corresponding to the changes
introduced in this PR.
- None added; this works on my machine, but I'm not clear on the root
cause of the issue and have no strong opinion on whether this is the
ideal way to fix it long term - simply leaning towards PR`ing a tenative
fix instead of raising an issue.
- [ ] I've made sure all auto checks have passed.
 - I am not familiar with these, but assume they will be run during CI.

---------

Co-authored-by: Leonardo Pinheiro <[email protected]>
Co-authored-by: Eric Zhu <[email protected]>

Resolves #5910

Co-authored-by: peterychang <[email protected]>

Resolves #5919

…y. (#5938)

Fixes issues like the following trace:

```
packages/autogen_ext/agents/file_surfer/_markdown_file_browser.py", line 39, in __init__
    self.set_path(self._base_path)
  File "/home/hmozannar/webby/.venv/lib/python3.12/site-packages/autogen_ext/agents/file_surfer/_markdown_file_browser.py", line 67, in set_path
    self._open_path(path)
  File "/home/hmozannar/webby/.venv/lib/python3.12/site-packages/autogen_ext/agents/file_surfer/_markdown_file_browser.py", line 210, in _open_path
    io.StringIO(self._fetch_local_dir(path)), file_extension=".txt"
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/hmozannar/webby/.venv/lib/python3.12/site-packages/autogen_ext/agents/file_surfer/_markdown_file_browser.py", line 248, in _fetch_local_dir
    mtime = datetime.datetime.fromtimestamp(os.path.getmtime(full_path)).strftime("%Y-%m-%d %H:%M")
                                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "<frozen genericpath>", line 67, in getmtime
PermissionError: [Errno 13] Permission denied: '/home/hmozannar/webby/autogen-studio/frontend/readme.txt'
```

To prevent accidental export of API keys

Currently we have SecretStr type for model clients to promote security
best practices.

- when we dump_component, keys are serialized  as SecreteStr ..
- when we load_component ... SecreteStr type is passed to the client in
the api_key field. This i causes the type problems as the clients expect
a string type.

This PR updates the from_config method for model clients to ensure we
get the value from SecretStr.

Closes #5944

use the latest version of llama-cpp-python to ensure `uv sync
--all-extras` don't fail on windows.

reference:
#5942 (comment)

Closes #6031 

---------

Co-authored-by: Eric Zhu <[email protected]>

Resolves #6096

Additionally: make sure MCP errors are formatted correctly, added unit
tests for mcp servers and upgrade mcp version.