feat: add body measurements support

[nicl-dev]

Feature Request

Summary

Add MCP tools for the Hevy body measurements API endpoint to enable AI assistants to read and log body weight and other measurements.

Hevy API Endpoints

• GET /v1/body_measurements - retrieve paginated body measurement history
• POST /v1/body_measurements - log a new body measurement entry

Proposed MCP Tools

• get-body-measurements - fetch measurement history (with page / pageSize params)
• create-body-measurement - log a new entry (weight, body fat %, etc.)

Use Case

Without access to body measurements, AI coaching workflows that use hevy-mcp are incomplete.

Currently, tools like Claude cannot retrieve weight history to:

• track progress toward a body composition goal
• correlate weight trends with training volume
• adjust caloric targets based on rate of weight loss/gain

[chrisdoc]

Hey @nicl-dev, thanks for the feature request! 🎉

This has now been implemented in #306 and is available in v1.23.0.

The following tools were added:

• get-body-measurements — Paginated list of body measurements
• get-body-measurement — Single measurement by date
• create-body-measurement — Create a new entry
• update-body-measurement — Update an existing entry