miniflare@4.20260210.0 — Workers SDK

#12469 2d90127 Thanks @petebacondarwin! - Add environment variables to control cf.json fetching behavior

You can now use environment variables to control how Miniflare handles the Request.cf object caching:
- CLOUDFLARE_CF_FETCH_ENABLED - Set to "false" to disable fetching entirely and use fallback data. No node_modules/.mf/cf.json file will be created. Defaults to "true".
- CLOUDFLARE_CF_FETCH_PATH - Set to a custom path to use a different location for caching the cf.json file instead of the default node_modules/.mf/cf.json.
This is particularly useful for non-JavaScript projects (like Rust or Go Workers) that don't want a node_modules directory created automatically.

Example:
```
# Disable cf fetching for all projects
export CLOUDFLARE_CF_FETCH_ENABLED=false
npx wrangler dev

# Or use a custom cache location
export CLOUDFLARE_CF_FETCH_PATH=/tmp/.cf-cache.json
npx wrangler dev
```
#12391 ce9dc01 Thanks @emily-shen! - Serve the local explorer UI from Miniflare

This bundles the local explorer UI into Miniflare, and if enabled, Miniflare serves the UI at /cdn-cgi/explorer.

This is an experimental, WIP feature.