Replace `?zip=1` / `?convert=docx|html|pdf` query forms with path-suffix
URLs that look like ordinary files. `<dir>.zip` and `<file>.docx` /
`.html` / `.pdf` are virtual files served by the dispatcher when stat
fails at the requested path AND the corresponding base resource exists:
GET /Project-1/archive.zip ← if archive/ is a real directory
GET /Project-1/notes.docx ← if notes.md exists
Real on-disk files always win — a genuine archive.zip in the tree
serves its bytes normally. The virtual forms only fire when nothing
real is there.
Why: the URL form lets clients emit plain <a href> without query-
string handling; `curl -O` writes a sensible filename; mirror tools
pick up the path through normal recursion; the protocol surface
becomes "every URL is a file". Bash + filesystem mental model.
Server:
- New helpers handler.RecognizeVirtualSubtreeZip /
RecognizeVirtualConvert (in subtreezip.go and converthandler.go).
- Dispatcher's stat-fails branch checks them between IsDefaultMdlSpec
and MatchAppHTML. ACL is enforced on the base resource (the source
directory for zip, the .md source for convert).
- Three legacy query-form branches removed from main.go.
Client:
- browse/js/download.js: `dir + '.zip'` instead of `dir + '/?zip=1'`.
- browse/js/preview-markdown.js: convert anchor hrefs become
`<mdUrl-minus-.md>.<fmt>` instead of `<mdUrl>?convert=<fmt>`.
- shared/zddc-source.js downloadConverted: same transform.
Tests: subtreezip_test.go test URLs cosmetically updated to the new
shape (the handler is exercised directly, so the URL is metadata only,
but the test reads better).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>