library: one address - Add books inside the staff site, plus Find a book

- Apache in the Koha container serves Quick Add at /add/ on the staff site
  (KOHA_QUICKADD_URL); koha now starts after quickadd so the name resolves
- Quick Add: relative API paths so it works at / and /add/; Add books / Find a
  book tabs; search by title, author or ISBN showing each copy's shelf and status
  (/api/search); Manage and Public catalogue links
- staff home gets a 'Library tools' block (HTML customizations, how Koha 26.05
  stores it) linking to Add books
- installer, kiosk add-on and READMEs advertise one main address; the public
  catalogue stays on its own port (Koha gives public and staff sites the same URL
  shapes, so they cannot share one address)

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013wi3ZSot4XbUViwRFgLpRf

library/install.sh

@@ -79,10 +79,10 @@ show_status() {
     fi
     dc ps
     echo
-    echo "  Catalogue (public):  http://$ip:$OPAC_PORT"
-    echo "  Staff interface:     http://$ip:$STAFF_PORT"
-    echo "  Add books (scan):    http://$ip:${QUICKADD_PORT:-8082}   (same login)"
-    echo "  Staff login:         $ADMIN_USER  /  $ADMIN_PASSWORD   (also stored in $HERE/.env)"
+    echo "  Your library:        http://$ip:$STAFF_PORT"
+    echo "      sign in here: add books at /add/ (or the 'Add books' button), find a book, lending, labels, people"
+    echo "  Public catalogue:    http://$ip:$OPAC_PORT   (search only - for a kiosk or visitors)"
+    echo "  Login:               $ADMIN_USER  /  $ADMIN_PASSWORD   (also stored in $HERE/.env; Add books asks once more with the same login)"
     echo
 }