Implements a Cloudflare Worker with:
- IndieAuth / OAuth 2.0 server (consent UI, PKCE, token issuance/introspection/revocation)
- Webmention receiver backed by KV, with list/get/delete API
- POSSE deploy-hook pipeline (Mastodon, Bluesky, Tumblr, Flickr)
- /setup endpoint returning ready-to-use head tag snippets and endpoint URLs
- Full integration guide in README

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>