Generalize the admin model from "single root super-admin" to a
delegated chain: a `<dir>/.zddc/admins` list grants admin authority
for that subtree, with a strict-ancestor rule preventing
self-elevation (you cannot edit the .zddc that grants your own
authority — only files strictly below it).
Add a guided server-rendered editor at /.admin/zddc/edit?path=<dir>
so subtree admins can manage their fiefdoms without filesystem
access. JSON API at /.admin/zddc covers GET (file + effective chain
+ can_edit), POST (atomic write + cache invalidation), DELETE,
plus a /tree endpoint listing every .zddc visible to the caller.
Optional theming via <root>/.admin.css.
Validation: glob syntax check, root-self-demotion rejection,
reserved-prefix path guard, YAML round-trip sanity. Writes are
atomic (temp file + fsync + rename) and invalidate the policy
cache.
Also includes the prior in-flight `Title` field on ProjectInfo
so per-project .zddc titles surface on the landing-page picker.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
