Attachments from incoming emails are uploaded to an optional Cloudflare R2
bucket and exposed as <enclosure> elements in RSS and <link rel="enclosure">
in Atom feeds, served at /files/{id}/{filename} with immutable caching.
R2 is opt-in: if ATTACHMENT_BUCKET is not bound the feature is a no-op.
Attachments are cleaned up from R2 on email/feed deletion and during
size-based feed trimming. Adds MockR2 to the test setup.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Mirrors the same pattern as cloudflare-email.ts — each provider has its
own adapter that translates provider-specific input into ProcessEmailInput
and delegates to processEmail(). inbound.ts is now a thin HTTP handler.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Julien Herr