Upgrades the mcp package dependency to 1.8.1

[ierickson]

MCP Integration Update for SSE Transport

Summary

This update implements compatibility with MCP 1.8.1, primarily addressing changes to the Server-Sent Events (SSE) transport system. The version has been incremented from 0.3.3 to 0.3.4.

Key Changes

Dependency Updates

• Updated mcp dependency from 1.6.0 to 1.8.1
• Added python-multipart as a transitive dependency from the MCP update

SSE Transport Adaptation

• Updated the FastApiSseTransport class to work with the new SessionMessage wrapper
• All messages are now properly wrapped in SessionMessage objects before sending
• Changed type hints and method signatures to accommodate the new message structure

Test Updates

• Updated tests to work with the new SessionMessage wrapper
• Fixed assertions to properly check message contents in the updated structure

Documentation Updates

• Added version 0.3.4 entry to the CHANGELOG

Technical Implementation

• Messages are now wrapped with SessionMessage in the accept_message method
• Error handling was updated to construct SessionMessage objects for error responses
• Type hints updated across the codebase to reflect the new message structure
• All tests were updated to maintain full test coverage

Build Updates

• Updated pyproject.toml with new version and dependency requirements
• Updated uv.lock file with latest dependency hashes and versions

Checklist before requesting a review

• Added relevant tests
• Run ruff & mypy
• All tests pass

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

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[tori-tadata]

Thanks so much for the fix, @ierickson . I just tested it on a sample MCP and can confirm it resolves the issue as expected. @shahar4499 — feel free to do a quick code review pass, but functionality-wise it looks good to me.