Add a configurable web_fetch ability with policy enforcement and action logging

[bradvin]

Summary

• add a new web_fetch ability with a default wp fetcher built on WordPress HTTP APIs
• validate request URLs with wp_http_validate_url() and keep v1 read-only with GET/HEAD
• enforce allow_network for network-capable abilities and log all web_fetch attempts through the action log helper
• add the fetcher registry/helper and unit coverage for success, validation, policy, truncation, and failure cases
• update docs, README, and generated assets to reflect the new ability and related runtime changes

Testing

• composer test
• npm run lint:php

[greptile-apps]

Your free trial has ended. If you'd like to continue receiving code reviews, you can add a payment method here.