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/i18n/en.json

@@ -685,6 +685,7 @@
   " · 未装备模组": " · No Module equipped",
   "已购买": "Purchased",
   "已招募": "Recruited",
+  "空栏位：刷新或下回合开始时补满": "Empty slot: filled by the next refresh or at the start of the next round",
   "再次点击确认升级（{price} 资金）": "Tap again to confirm upgrade ({price} Funds)",
   "升级调度中心（{price} 资金） · {key}": "Upgrade Dispatch Center ({price} Funds) · {key}",
   "已满级": "Max Level",
@@ -781,6 +782,7 @@
   "观战席": "Spectators",
   "移出观战者 {name}": "Remove spectator {name}",
   "移出该观战者": "Remove this spectator",
+  "观战者不占博士席位，只能观看；创建者可以把观战者移出，被移出的人不再收到战场画面。": "Spectators take no Doctor seat and can only watch; the Host can remove a spectator, who then no longer receives the battlefield.",
   "入座": "Take a Seat",
   "移出同盟": "Remove from Alliance",
   "确定将「{name}」移出同盟吗？对方可以凭同盟密钥重新加入。": "Remove \"{name}\" from the Alliance? They can rejoin with the Alliance Key.",
@@ -916,6 +918,22 @@
   "地面单位可通过": "Ground units can pass",
   "地形机制": "Terrain Mechanics",
   "这一格": "This Tile",
+  "场地装置": "Stage Device",
+  "装置机制": "Device Mechanics",
+  "挡在地面上的工事：地面敌人会绕开它走；只有无路可走时才会撞上来，把它摧毁后继续前进": "An obstacle on the ground: ground enemies walk around it, and only run into it when there is no other way through, destroying it before moving on",
+  "生命 {hp} 点，被摧毁后从场上消失": "{hp} HP; it disappears from the battlefield once destroyed",
+  "自动攻击射程内的一名敌人，造成法术伤害，命中的敌人附加脆弱": "Automatically attacks one enemy in range for Arts damage; the enemy hit is inflicted with Fragile",
+  "按当前层数最高的盟约计算：每 1 层，攻击速度 +{aspd}（至多 +{aspdMax}），附加的脆弱 +{frag}%（至多 +{fragMax}%）": "Scales with the Alliance that currently has the most stacks: per stack, ASPD +{aspd} (up to +{aspdMax}) and the Fragile it inflicts +{frag}% (up to +{fragMax}%)",
+  "脆弱持续 {sec} 秒": "The Fragile lasts {sec} {sec|second|seconds}",
+  "高台位装置：地面敌人不能走上这一格": "A high-ground device: ground enemies cannot walk onto this tile",
+  "远程位干员可以部署在其上；站上去的干员在高位，不阻挡敌人": "Ranged-position Operators can be deployed on it; an Operator standing on it is on high ground and does not block enemies",
+  "向前方 {n} 格吹出气流（这一台朝{dir}）": "Blows an airflow {n} {n|tile|tiles} ahead (this one faces {dir})",
+  "朝向与风向相同的攻击力 {v}": "ATK {v} when facing the same way as the airflow",
+  "相反的 {v}": "{v} when facing the opposite way",
+  "部署在气流里的干员：{mods}": "Operators deployed in the airflow: {mods}",
+  "顺风移动速度 ×{v}": "Movement Speed ×{v} moving with the airflow",
+  "逆风 ×{v}": "×{v} moving against it",
+  "在气流里移动的敌人：{mods}": "Enemies moving in the airflow: {mods}",
   "全部清空": "Clear All",
   "清空全部 {n} 个自选名额？": "Clear all {n} Custom Squad {n|slot|slots}?",
   "文件过大，请选择「导出」下载的自选编队文件": "The file is too large. Choose a Custom Squad file downloaded with \"Export\".",