Fixed connection resource leaks when Client.connect() fails during transportation or initialization. Also addressed several Zod v4 compatibility issues and test timeouts.

Motivation and Context

• Connection Leak: Previously, if super.connect(transport) failed (e.g., process failed to spawn), the Client would bypass its cleanup logic, leaving danging transport resources.
• Zod v4 Compatibility: Certain schemas like z.record(z.unknown()) caused crashes in Zod v4. Additionally, using the Zod v4 Mini engine to parse V4 Classic schemas led to internal TypeErrors.
• Test Stability: The integration tests were occasionally timing out on slower environments due to the cold-start time of tsx.

How Has This Been Tested?

• Added a new unit test in test/client/index.test.ts specifically verifying that transport.close() is called if connect() fails.
• Fixed Zod v4 syntax in protocol.test.ts and taskLifecycle.test.ts.
• Verified that all tests pass successfully locally using pnpm test.

Breaking Changes

None

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update

Checklist

• I have read the MCP Documentation
• My code follows the repository's style guidelines
• New and existing tests pass locally
• I have added appropriate error handling
• I have added or updated documentation as needed

Additional context