Operator battle voices: the official combat lines play by voice slot during battles, one at a time (#73)

Deploy, skill and result lines come from the operators' official voice slots; a newer line takes the channel over (stale callbacks of the replaced line no longer release it), and the result line is spoken by an operator of the player's own battle. Contributed by @Convey123.

docs/DESIGN.md

@@ -1476,6 +1476,20 @@ Two public GitHub issues after 0.1.0, both client-only. Normative lines rewritte
 - Tests: `test/sim/feedback1-tank-triggers.test.js` (the data, kit = data, the real battle for the six and for every other MANUAL 重装 record), `test/data.test.js`, `kits_t1t2` / `kits_alt_t1` (PR #12's), `kits_alt_t2` (灰毫 S2), `kits_t5` / `kits_alt_t5` (号角), `test/docs-consistency.test.js`.
 - Extended 2026-10-04: 余 S2 (SKILL_RANGE on its x-1, §22.10); 14 records deviate now.
 
+### 21.30 干员战斗语音: an operator's official lines, in battle only (user request, 2026-10-03) — `tools/assets/plan.mjs` (`voiceSlots`), `tools/assets/audio.mjs` (`indexVoice` / `VOICE_SLOTS` / `VOICE_BATTLE_SLOTS` / `VOICE_PREP_SLOTS` / `VOICE_DIRS`), `tools/assets/cache.mjs`, `tools/fetch-assets.mjs --voice-lang / --voice-all`, `public/js/audio.js` (`VOICE_PRIORITY` / `VOICE_COOLDOWN_MS` / `VoiceGate` / `resultVoiceSlot` / `resultSpeaker` / `voice()`), `server/sim/ai.js performAttack 'engage'`, `battle/runner.js emit('result')`, `screens/game.js onResult`, `ui/detailPanel.js voice`, `ui/settings.js`, `ui/gameLogic.js sanitizeSettings`
+
+User: 「给每个卫戍干员都加语音」, then, after the first build, 「整备阶段不需要干员语音，战斗开始后才需要语音，也就是只需要作战中语音」.
+
+**Where the lines come from.** Every operator the mode can field already has official battle lines in the same voice dump the BGM and SFX come from — `voice_cn/{charId}/cn_nn.mp3` (JP/EN/KR: `voice/`, `voice_en/`, `voice_kr/`, the same file names, `tools/fetch-assets.mjs --voice-lang=jp|en|kr`). `charword_table.json`'s `placeType` says when each line is used, and `indexVoice()` turns it into the manifest's `audio.voice[charId]`: 行动出发 `start` (BATTLE_START), 行动开始 `faceEnemy` (BATTLE_FACE_ENEMY), 选中干员 `select`, 部署 `place`, 作战中1-4 `skill1..skill4` (BATTLE_SKILL_N), 编入队伍 `squad`, 任命队长 `squadFirst`, 结算 `resultFour/Three/Two/Lose` (完成高难行动 / 3星结束行动 / 非3星结束行动 / 行动失败) and 干员报到 `gacha`. A slot with several lines stays an array and the client draws one. Only the base word key is planned (`wordKey === charId`): the dump has no folder for a skin variant's word key (`char_x_ita`, `char_x_epoque#28`), so those lines 404. **Only the slots a battle can play are planned** (`audio.mjs VOICE_BATTLE_SLOTS`): 干员报到 / 编入队伍 / 任命队长 are lines of the official client's own 养成 / 编队 UI, nothing in this mode ever requests them (`test/docs-consistency.test.js` checks the client's `voice(...)` call sites), and downloading them cost 360 files (19.3 MB) on every run — `--voice-all` adds them back for the complete official set. Measured: 120 of the 121 in-mode charIds have a full set — the 17 预备干员 and the mode's own 盟约·辅助干员 have no battle voice at all, so they simply get no entry — 1680 lines of the 2040 upstream, in a manifest of 5694 files / 324.2 MB (files and `stats.voiceChars` in `data/assets.json`).
+
+**Where each line plays — battle only.** Every line comes from a running battle's own event stream or from its settlement, so no hook needs a phase check and the 休整期 stays silent: the shop does not say 干员报到 (a merge-completing buy neither says 任命队长), a retreat does not say 编入队伍 and dragging a piece onto the board in prep says nothing. In battle: 开战 — the first operator deployed says 行动出发 and the others 部署 (the sim's `deploy` events; `setFieldUnits` resets the flag per field — in this mode every piece enters at once, which is why the gate below exists, and a knocked-out operator's redeploy says 部署 again); 接敌 — the sim's new `['engage', id]` (a unit's first attack that hits an enemy, official ENCOUNTER_ENEMY); 技能 — `skillN` from the unit's `skillIndex` (作战中1-4); 选中 — the detail panel opening on an operator **while a battle runs** (`DetailPanel voice` = the game screen's `combat`); 结算 — `resultVoiceSlot()`: 完美作战 ⇒ 3星结束行动 (绝境 / 终极 ⇒ 完成高难行动), 有漏怪 ⇒ 非3星结束行动, 一个没杀 ⇒ 行动失败, spoken by a drawn operator **of that battle's own field** (`resultSpeaker`, from the result's `perPlayer.unitsEnd`: the operators of that field, survivors first, a summon piece never), driven by the runner's new `emit('result', …)` — never the field on screen, so watching a teammate cannot put their operator's voice on the viewer's settlement line (review on #73).
+
+**Why a channel, not SFX.** Voices are 1–4 s long and a battle deploys eight operators, then fires dozens of skills; playing them like SFX would flood the mix. `VoiceGate` copies the official scheduling data (`audio_data.json battleVoice.voiceTypeOptions`): one line at a time, a 1.2 s global gap, a per-unit per-slot cooldown (10 s for 作战中, 3 s for 接敌, 1.5 s for 选中) and takeover when a line's priority beats the playing one by a margin (the official 0.1 s `crossfade`) — the priorities are the official ones (BATTLE_START 100, ENCOUNTER_ENEMY 90, SKILL_ACTIVE 70, PLACE_CHAR 20, FOCUS_CHAR 10) and the settlement lines get 85, above 作战中 but below 接敌. Every deferred step of a line — its decode, its `onended`, the safety timer — carries its own token and returns without touching the gate once it is stale, so a line taken over while it was still loading can never free the channel its replacement just took (review on #73). The channel has its own gain and its own slider (设置 干员语音 / VOICE; `sanitizeSettings` adds `voice`, so a saved profile without it keeps the default and players can turn voices down without losing SFX). The buffer cache also gained a decoded-PCM budget (64 MB) beside its 180-entry cap: a voice decodes to ~0.4–1.3 MB, and 180 of them would be ~100 MB.
+
+**[ASSUMED].** 接敌 as "the unit's first attack on an enemy" (the official trigger is the first enemy it encounters, not necessarily one it hits) and the settlement mapping (漏怪 ⇒ 非3星, 完美作战 in 绝境 / 终极 ⇒ 完成高难行动) are our readings. Lines follow the field on screen: watching a teammate's battle (前往查看) plays *their* operators' lines, while the settlement line fires for the player's own battle only (`e.own`, `battle/runner.js`) and is spoken by an operator of that battle's own field (`resultSpeaker`). 部署 and 选中干员 stay in the plan although the official groups them with the prep lines: a battle *does* play them (the first operator says 行动出发 and the others 部署, and the detail panel says 选中 while a battle runs), so only the three slots no call site ever asks for are dropped — `VOICE_PRIORITY` / `VOICE_COOLDOWN_MS` keep every level, so `--voice-all` restores 编入队伍 / 任命队长 / 干员报到 for the day the 休整期 speaks again.
+
+- Tests: `test/ui/audio.test.js` (the priority table, the settlement slot and its speaker, the gate's global gap / per-unit cooldown / takeover, the stale-callback regression, and the battle events that drive the lines against a fake Web Audio), `test/ui/gameLogic.test.js` (the `voice` setting), `test/sim/battle.test.js` (the wire format: every emitted tuple is a known `EV` — the new `engage` included); the manifest's 1680 voice paths are covered by `test/assets.test.js`.
+
 ## 22. GitHub issues after 0.1.1 (v0.1.2)
 
 Public GitHub issues filed after the 0.1.1 release (2026-10-03), each triaged against 0.1.1 first; the real ones were fixed for 0.1.2 in fix branches WA–WL, each independently reviewed before it was merged into `feedback2`. Where each is handled: #25 back-facing operators keep their attack pose when knocked out → §22.1; #51 突袭's idle redeploy → §22.2; #33 items 1–2 阿戈尔's devour and 乌尔比安 S3 → §22.3; #33 item 6 活性源石, with the 沼泽 and 深水区 terrain → §22.4; #42 emotes and guide pages without a local client, and the English title (#38) → §22.5; #32 item 4 钩索师 / 推击手 on 高台 → §22.6; #52 史尔特尔's 余烬 → §22.7; #43 an enemy's 隐匿 after a block, and the 深池逐火 ember window → §22.8; #32 item 7 荒芜拉普兰德 S3's drones → §22.9; #32 item 1 余 S2 → §22.10; #44 归溟幽灵鲨's 替身 → §22.11; #32 item 6 enemy splash against a 隐匿 operator → §22.12; #35 / #16 (PR #48) 要塞 against air units and 莫斯提马's slow icon → §22.13; #58 / #60 / #64 follow in §22.14–§22.16. Decisions of the owner, 2026-10-04: 荒芜拉普兰德's drones measure the distance to an enemy's position, a huge enemy's centre (§22.9); 余 S2 casts with an enemy on its x-1 — a deliberate deviation from the official TAKE_DAMAGE row, added to §21.29's six (§22.10); 乌尔比安 keeps the devour gains through his 【移动】 — the deviation stays (§22.3).