feedback1 final: merge the client fixes for GitHub issues #5 (prep camera follows the folded shop) and #8 item 5 (operators no longer stay placeholders)

Conflicts resolved keeping both sides:
- CHANGELOG 0.1.1 界面: the three gaps lines, then the issue #5 and #8 lines.
- DESIGN: the branch's "§21.26 Client fixes for GitHub issues #5 and #8" follows the gaps' §21.26 as §21.27; its
  references in §9 (setCamera `shop`, the model fallback), §17.1 (the quiet budget) and §19.8 (the collapsed shop)
  now point at §21.27.

public/css/devices.css

@@ -129,6 +129,11 @@ html:not(.sp-in-match) .toast-host { margin-top: var(--sa-t); }
   .gm__corner { width: max(96px, calc(3 * max(.56rem, 34px) + .2rem)); }
   .dpanel:not(.dpanel--right) { bottom: calc(.44rem + max(1.51rem, 96px) * 55 / 151 + max(.56rem, 34px)); }
 }
+/* With the shop folded (收起) no bar covers the corner: one row again, so the folded shop's prep camera, which keeps the
+   bench above the corner's hit areas (ui/fieldHost.js hudBands), grows the board on narrow phones too (public issue #5). */
+@media (max-width: 767px) {
+  .gm.is-collapsed .gm__corner { flex-wrap: nowrap; width: auto; }
+}
 
 /* Short landscape phones (≤ 460 CSS px tall, 1rem = 40 px): the lobby's two columns are compressed so the
    创建同盟 button and the join panel stay on screen without scrolling. The detail card's header is shorter (no