The top-level catch-all silently redirected unknown paths to "/", and the
nested /admin/*, /p/:projectId/*, and /docs/* route groups had no catch-all
(invalid subpaths rendered a blank pane). Add a shared NotFound component and
wire it into all four route groups so a bad/typo'd URL shows a clear 404 with
a link home. Client-side 404 UI (SPA still serves HTTP 200).
Patch 0.52.2 → 0.52.3; CHANGELOG updated. Caught by the operator on PPE.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Ben Stull