Add mocked tests for MCP tool modules

[MattyMailers]

Goal

Expand mocked Vitest coverage across the MCP tool modules so contributors can safely add endpoints without breaking path/query/body contracts.

Suggested scope

• Mock SmartMovingClient for one tool module at a time.
• Assert endpoint paths and query casing.
• Assert create/update request body shape.
• Assert API failures return isError: true.
• Use fake data only.

Good first module choices

• reference.ts
• communication.ts
• followups.ts

Done when

• At least one tool module has meaningful mocked tests.
• npm run verify passes.