Permission ticks centred under their headers; tick, radio and switch edge back to --line-ctrl

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

src/screens/admin/Admin.module.css

@@ -60,7 +60,8 @@ it goes FIRST so the strip lands above what it indexes and not under it.
 
 /* The matrix's EDITABLE checkbox: 18 px tall, and until now not enlarged. The
    read-only one is `ui/Matrix`'s, is disabled and is no target for anything. */
-.chkPerm { composes: hitArea from '../../ui/interaction.module.css'; margin: 0 auto; display: block; }
+/* The ReUI checkbox carries its own hit area; this only centres it under its header. */
+.chkPerm { display: flex; justify-content: center; }
 
 @media (max-width: 960px) {
   .withIndex { grid-template-columns: minmax(0, 1fr); }