docs: update server SDK guidance for 0.7

[JJasonSun]

Summary

• update the current TypeScript and Python package versions to 0.7.0
• document the stable Goal Runs surface and nullable call_id
• link only the public TypeScript source while the Python repository remains private

API contract

Synchronized openapi/calle.openapi.yaml with the public TypeScript SDK 0.7.0 contract. The affected surface is Goal listing readiness, Goal response statuses, and the nullable Goal Run call_id.

Checklist

• I kept the change focused and public-facing.
• I removed secrets, private URLs, phone numbers, and customer data.
• The OpenAPI change matches the published 0.7.0 SDK contract.
• I updated tests when observable site behavior changed.
• Screenshots are not applicable; there is no layout change.
• I ran pnpm run validate.