Three coupled fixes:
1. landing MDL card: Open button now navigates to /<project>/archive/
<party>/mdl (no trailing slash) so the tables tool loads. The
slash form would route to browse instead, which is not what users
want when they click "Open MDL".
2. zddc-server canonical-folder fallback extended to
archive/<party>/{mdl,incoming,received,issued}. New
zddc.IsArchivePartyFolder() recognises any of the four party
folders at depth 4. fs.ListDirectory returns [] for missing
on-disk variants (mirroring the project-root behavior added in
commit 3fc3717); the dispatcher routes slash forms to
ServeDirectory and the no-slash mdl form to ServeTable, with
non-mdl no-slash forms 302'ing to the slash form.
So /Project-N/archive/<party>/incoming/ now lands on an empty
browse listing rather than 404 when nobody has dropped files yet.
3. Fixture seeded with 3 files per party under incoming/ — naming
intentionally NOT in transmittal-envelope form, so classifier
(loaded automatically by browse's grid mode at /incoming/
per the URL-driven view convention) has something to rename.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>