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/ui/settings.js

@@ -4,10 +4,13 @@
 // while the current language's pack is a machine translation, `_meta.machineTranslated`) and the 快捷键
 // section that rebinds the in-match shortcuts (the key map: ui/gameLogic/shortcuts.js; the community request
 // 「快捷键可不可以自己设置」, the owner's decision of 2026-10-07) and 问题反馈, which copies the diagnostics of this page
-// for a bug report (diag.js: the error log, this browser, optionally the battle on screen; nothing is uploaded).
+// for a bug report (diag.js: the error log, this browser, optionally the battle on screen; nothing is uploaded). The
+// lobby and the room open it from a 设置 button next to 玩法说明 (SettingsButton, GitHub #238); the title screen and the
+// match have their own gear.
 
 import { useLayoutEffect, useRef, useState } from '../../vendor/hooks.module.js';
 import { html, Modal, Button, Icon, MicroLabel } from './components.js';
+import { GIcon } from './gameComponents.js';
 import { createStore, useStore, loadPref, savePref, store } from '../store.js';
 import { sanitizeSettings, HOTKEY_ACTIONS, DEFAULT_HOTKEYS, hotkeyLabel, rebindHotkey, isDefaultHotkeys, captureHotkey, VOICE_LANGS } from './gameLogic.js';
 import { audio } from '../audio.js';
@@ -247,3 +250,16 @@ export function SettingsModal({ open, onClose }) {
     </div>
   <//>`;
 }
+
+/**
+ * The 设置 button of the lobby and the room (GitHub #238 — before it the settings were reachable only from the title
+ * screen and a running match): the twin of the 玩法说明 button (ui/guide.js GuideButton), with the settings modal behind it
+ * (mounted only while open). The same modal as the title screen's and the match's: nothing in it is match-only.
+ * @param {{ class?: string, size?: 'sm'|'md'|'lg'|'xl', variant?: string, label?: string }} props
+ */
+export function SettingsButton({ class: cls, size = 'sm', variant = 'ghost', label = t('设置') }) {
+  const [open, setOpen] = useState(false);
+  return html`<${Button} variant=${variant} size=${size} class=${cx('settings-btn', cls)} onClick=${() => setOpen(true)}
+      title=${t('设置')} aria-label=${t('设置')} data-testid="settings-btn"><${GIcon} name="gear" class="btn__icon" />${label}<//>
+    ${open ? html`<${SettingsModal} open=${true} onClose=${() => setOpen(false)} />` : null}`;
+}