Add get_reference_snapshot compound tool

[MattyMailers]

Goal

Add a compound get_reference_snapshot tool that fetches common SmartMoving reference values in one call.

Why

Agents often need branches, users, move sizes, service types, referral sources, tariffs, and reason lists before creating or updating CRM records. A single snapshot tool reduces missed setup calls.

Suggested response

Return a JSON object with sections for each reference collection and safe error details if one section fails.

Done when

• Tool is implemented with Zod schema/description.
• Mocked tests cover endpoint calls and response shape.
• README/tool catalog is updated.