Fixed CLI tests that depended on specific version of server-everything

[BobDickinson]

Summary

CLI tests depended on specific functionality of server-everything, which has changed, breaking a number of tests.

This PR:

• Pins server-everything (in CI and tests)
• Fixes all tests to work with current pinned version
• Fixes a problem with undetected failures (isError: true payloads).

Type of Change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Documentation update
• Refactoring (no functional changes)
• Test updates
• Build/CI improvements

Testing

• Tested in UI mode
• Tested in CLI mode
• Tested with STDIO transport
• Tested with SSE transport
• Tested with Streamable HTTP transport
• Added/updated automated tests
• Manual testing performed

Test Results and/or Instructions

All tests now pass

Checklist

• Code follows the style guidelines (ran npm run prettier-fix)
• Self-review completed
• Code is commented where necessary
• Documentation updated (README, comments, etc.)

Breaking Changes

No