feedback7: merge fb7-ui-backlog — #229 device tooltips, #238 settings button in lobby / room, #138 准备 folds the shop, #120 in-match spectator roster (cap stays 2), PR #308 capsule counts (+ the shared-field progress fix), PR #333 empty new shop slot on 调度中心 upgrade

- Conflicts: the stats entry (merged fb7-stats) and the settings button both sit in the lobby / room top bars — both kept;
  public/js/ui/settings.js (#321 diagnostics, voiceLang, SettingsButton); docs/PLAYING.md table rows resolved line by
  line against the merge base (#368, #354, #333 edits kept); docs/SIM.md / design/network.md snapshot field lists
  (resolved + ammo / wolves / neg / stand / standCut); design/client.md Screens line (#368's AI switch kept).
- Grok review: MERGE AFTER FIXES — the shared-field capsule finding fixed on the branch (1a880699).
- Golden: roster 23, bonds 2, fields 11, matches 18, diy 11 — #308 totals / snapshots and #333's shop RNG (union OK);
  broad node --test 5473 (5472 pass, 0 fail, 1 skipped); lint 0 errors; typecheck; i18n strict clean.

public/js/screens/room.js

@@ -20,6 +20,7 @@ import { toast, toastError } from '../ui/toasts.js';
 import { copyText } from '../ui/clipboard.js';
 import { GuideButton } from '../ui/guide.js';
 import { openStats } from './stats.js';
+import { SettingsButton } from '../ui/settings.js';
 import { LoadoutButton } from './loadout.js';
 import { net } from '../net.js';
 import { store, useStore, shallowEqual, emptyMatch, isSpectating } from '../store.js';
@@ -308,6 +309,7 @@ export function RoomScreen() {
           <${MicroLabel}>${t('当前延迟')}<//>
         </div>
         <${Button} variant="secondary" size="sm" icon="chart" class="stats-entry" onClick=${openStats} title=${t('统计数据')} aria-label=${t('统计数据')}>${t('统计')}<//>
+        <${SettingsButton} class="room-settings" variant="secondary" label=${t('设置')} />
         <${GuideButton} class="room-guide" variant="secondary" label=${t('玩法说明')} />
       </div>
       <div class="topbar__center">