security: add msgpack as direct dependency for security fix

Add msgpack>=1.2.0 as a direct dependency to ensure the security
fixes for Unpacker reuse vulnerability are properly enforced.

The dependabot PR #67 already updated msgpack from 1.1.2 to 1.2.1 in uv.lock,
but adding it as a direct dependency ensures the security constraint is
explicitly declared and maintained.

Security fixes in msgpack 1.2.1:
- Harden Unpacker.__init__ re-entry cleanup to prevent buffer/context leaks
- Fix use-after-free in get_data_from_buffer
- Avoid memory leak when decoding invalid nested arrays
- Check return codes in unpack callback functions

Also fix ruff formatting issue in doctor.py docstring.

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Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

Author: johnteee

pyproject.toml

@@ -25,6 +25,7 @@ classifiers = [
 dependencies = [
     "bandit>=1.9.4",
     "cryptography>=48.0.1",
+    "msgpack>=1.2.0",
     "python-multipart>=0.0.31",
     "starlette>=1.3.1",
 ]

teaagent/cli/_handlers/_doctor.py

@@ -1005,7 +1005,7 @@ def doctor_config_lint_command(args: argparse.Namespace) -> int:
 
 def print_json(value: Any) -> None:
     """Doctor-specific JSON output with additional sanitization layers.
-    
+
     This function applies doctor-specific redaction before delegating to the
     centralized print_json function for final serialization and output.
     """