revert(orbit): drop maxPending cap feature, keep suggestion mute

The pending counter desynced from the actual approval list (state.queue
holds approved items as history, so the count never decreased after a
host approve). The host-pushed pendingApprovalCount workaround didn't
hold up under live testing either, so we're rolling the whole cap
feature back rather than ship something flaky.

What's gone:
- OrbitSettings.maxPending + state.pendingApprovalCount
- cap branch in applyOutboxSnapshotsToState (now back to mute-only)
- maxPending number input in settings popover
- pending counter chip in OrbitQueueHead
- 'cap-reached' branch in evaluateOrbitSuggestGate / OrbitSuggestGateReason
- cap-related toasts in ContextMenu / useOrbitSongRowBehavior
- cap-related i18n keys (suggestBlockedCap, settingMaxPending*, pendingCounter*)
- cap CSS (.orbit-queue-head__pending, .orbit-settings-pop__number)

What stays: per-guest suggestion mute (works correctly) and everything
that fed into both features (OrbitState.suggestionBlocked,
setOrbitSuggestionBlocked, evaluateOrbitSuggestGate, the participants
popover Mic/MicOff toggle, the suggestBlockedMuted toast).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/locales/zh.ts

@@ -1583,12 +1583,7 @@ export const zhTranslation = {
     settingAutoShuffleHint: '即将播放队列的定期 Fisher-Yates 洗牌。关闭：顺序仅在你手动重新排列时改变。',
     settingShuffleInterval: '洗牌间隔',
     settingShuffleIntervalHint: '会话运行时即将播放队列的重新洗牌频率。',
-    settingMaxPending: '最大待审投歌数',
-    settingMaxPendingHint: '同时等待审核的访客投歌上限。0 = 不限制。',
-    pendingCounter: '{{count}} / {{max}} 待审',
-    pendingCounterTooltip: '等待中的访客投歌 / 上限',
     suggestBlockedMuted: '主持人已禁止你在本场会话投歌。',
-    suggestBlockedCap: '审核队列已满，等主持人处理一些再继续。',
     settingShuffleIntervalValue_one: '{{count}} 分钟',
     settingShuffleIntervalValue_other: '{{count}} 分钟',
     settingShuffleNow: '立即洗牌',