Entries and history are keyed by feed id, so changing a URL keeps them -- the point being that a feed URL can carry an auth token that gets rotated. Changing it clears the stored ETag/Last-Modified, which belong to the old URL and could otherwise produce a bogus 304. The copy button cannot use navigator.clipboard: that needs a secure context and this is served over plain HTTP on a LAN address. Falls back to execCommand. Invalid input now returns 400 rather than 500. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01RPyeapneuXrCdojsaiXGbe