Fix zod mismatch issue. Fixes npm i

[matteo8p]

Currently, when you run npm i, it triggers a build script that breaks. See this issue.
#32

There was a mismatch in zod versions being used. The SDK requires zod v4 but the project impored zod v3. We update the imports in app-bridge.ts and types.ts to use zod v4.

After:

Motivation and Context

Fixes broken npm i

How Has This Been Tested?

I ran npm i and confirmed that the build works and dependencies are properly installed.

Breaking Changes

NA

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

NA

[ochafik]

Thanks @matteo8p !