chore: v2.8.5 — Trash opens on one folder per user, server setup installs S3

- Files → Trash: ONE sidebar entry. An admin's opens on a folder per user's
  Trash (My Trash first, item counts from GET /api/homes/trash, an unreadable
  one showing its error); a folder opens that user's Trash (path bar
  Trash › user, Up back to the folders). An admin may restore/purge in
  another user's Trash (audited); purging asks first. The merged "All users"
  list is gone from the UI.
- A home's Trash is its user's whole recycle bin (home store + host store,
  items tagged `store`).
- `agenthub server setup` installs one Linux user per account on Linux by
  default (`--no-system` opts out); install-system messages drop `sudo`.
- Settings → Git: the author email suggests <username>@<AGENTHUB_EMAIL_DOMAIN>.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

client/src/pages/__tests__/__snapshots__/screens.snapshot.test.tsx.snap

@@ -7178,7 +7178,7 @@ exports[`screen snapshots > Settings — about 1`] = `
                 <span
                   class="text-status-warning/90"
                 >
-                  UI build v2.8.4 (rebuild client to match)
+                  UI build v2.8.5 (rebuild client to match)
                 </span>
               </p>
             </div>