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/ASSETS.md

@@ -19,7 +19,9 @@ npm run assets       # = node tools/vendor.mjs && node tools/fetch-assets.mjs
 | `--force` | Re-download everything. |
 | `--offline` | No network. Re-runs post-processing (atlas fixes, skeleton parsing, WOFF2) on what is already on disk, then rebuilds `data/assets.json`. |
 | `--dry-run` | Print the plan (file and model counts, alias notes) and exit. |
-| `--refresh-index` | Re-download the two upstream indexes: `audio_data.json` and `models_data.json`. |
+| `--refresh-index` | Re-download the upstream indexes: `audio_data.json`, `charword_table.json` (the 干员战斗语音 slots) and `models_data.json`. |
+| `--voice-lang=cn` | 干员战斗语音 language: `cn` (default) | `jp` | `en` | `kr` — the same file names under `voice_cn/`, `voice/`, `voice_en/`, `voice_kr/`. |
+| `--voice-all` | Plan every official voice slot, including the prep-only lines no battle plays (干员报到 / 编入队伍 / 任命队长 — 360 files, one per operator and slot). Off by default: nothing requests them, so planning them only makes every run download more. |
 | `--prune` | Delete files under `public/assets/` that the manifest no longer references, for example after a mapping change. Without this flag they are only listed in the report. `public/assets/local/` (written by `tools/local-extract`) is never pruned. Implies `--allow-shrink`. |
 | `--allow-shrink` | Write `data/assets.json` even when it loses entries the current one has (see "The manifest never shrinks by accident" below). |
 | `--local-spines` | Rewrite `tools/assets/local-enemy-spines.json` (the metadata of the enemy models only the local client has, see "Enemy aliases") from the models `tools/local-extract/extract.py` extracted to `public/assets/local/spine/enemy/`. Run it after a game update changed them; without it the committed file is used and a differing extraction only gets a warning. |
@@ -31,7 +33,9 @@ audio entries short — all 42 still resolve upstream; PR #7). When the rebuilt
 one, the run keeps the current file, prints the entries it would drop (also in the report: `droppedEntries`,
 `manifestWritten: false`) and exits 1. Re-run to retry the downloads, or pass `--allow-shrink` (or `--prune`) when the
 smaller manifest is intended, for example after a mapping change. Build fields (`version`, `hash`, `generator`,
-`stats`), new entries and a changed value are never a drop (`tools/assets/manifest.mjs droppedEntries`).
+`stats`), new entries and a changed value are never a drop (`tools/assets/manifest.mjs droppedEntries`). A run whose
+plan legitimately narrows — like the 干员战斗语音 default, which no longer plans the three prep-only slots (360 entries,
+DESIGN §21.30) — reports exactly those entries and needs `--allow-shrink` once; the list it prints is the check.
 
 The script is **idempotent**. A file on disk is kept, not re-downloaded, when any one of these holds:
 - its size matches the ledger entry from a previous download (`.cache/assets-ledger.json`);
@@ -48,7 +52,7 @@ How downloads are fetched:
 - A manifest entry with fallbacks (for example an enemy icon that falls back to its base enemy's icon) only moves on to the next alternative after a **definitive 404**. When the primary fails transiently (network error, 5xx or an invalid payload after all retries), no fallback is fetched. The path is listed under `downloadErrors` in the report, and the next run retries the primary.
 - A skeleton that fails to parse is deleted and removed from the ledger, so the next online run downloads it again.
 
-The first run downloads about **269 MiB in about 4,000 files** (it took 134 s on a ~3 MB/s link before the 55 emote and 玩法说明 files, 21.3 MiB, were added). A re-run takes about 1 s.
+The first run downloads about **309 MiB in about 5,690 files** (it took 134 s on a ~3 MB/s link before the 55 emote and 玩法说明 files, 21.3 MiB, and the 1,680 干员战斗语音 files, 40.1 MiB, were added). A re-run takes about 1 s. The voice count is the twelve slots a battle plays; the three prep-only slots the official client uses elsewhere (干员报到 / 编入队伍 / 任命队长, 360 more files, 18.4 MiB) are left out unless `--voice-all` is passed.
 
 Outputs:
 - `data/assets.json`: the manifest (committed).
@@ -86,6 +90,7 @@ The research JSONs in `docs/research/` (03, 05, 07) define **which** ids are nee
 | Enemy Spine that no dump carries (灼热源石虫 / 炽焰源石虫) | the local client only (`tools/local-extract/extract.py ENEMY_SPINES`, optional); never downloaded and never required: an overlay of the web alias (`enemies[id].spineLocal`) | `local/spine/enemy/{enemyId}/{stem}.*` (listed in `data/local-assets.json`) |
 | BGM | AA2 `voice` branch `audio/sound_beta_2/music/**` (大厅/休整期 `act1autochess`, 开战 `act13side/m_bat_kazimierz2_{1,2}` — 骑士之日 / 无畏者; the 开战 track follows the round: `_2` 无畏者 rounds 1–7, `_1` 骑士之日 from round 8) | `audio/bgm/{file}.mp3` |
 | SFX (UI, battle, per unit) | AA2 `voice` `audio/sound_beta_2/**`, mapped from `audio_data.json` banks | `audio/sfx/{same sub-path}.mp3` |
+| 干员战斗语音 | AA2 `voice` `audio/sound_beta_2/voice_cn/{charId}/cn_nn.mp3` — the lines `charword_table.json` lists (`placeType` = when the game plays one, `voiceAsset` = the path); `--voice-lang=jp|en|kr` takes the same file names from `voice/`, `voice_en/`, `voice_kr/` | `audio/voice/{lang}/{charId}/{cn_nn}.mp3` |
 | Fonts: Bender Regular and Light, Novecento Wide | TimWangZi/The-font-of-Arknights | `public/fonts/*.{otf,ttf,woff2}`, `public/fonts/fonts.css` |
 
 The `stem` of a Spine model is the upstream file name. Two examples: `char_107_liskam` has the stem `char_107_liskarm`, and `enemy_9032_aclionk` uses `enemy_1559_vtlionk`. The skel and atlas of a model always share one stem. pixi-spine locates the atlas by swapping the extension, so this matters.
@@ -136,7 +141,7 @@ All paths are URL paths relative to the site root, for example `/assets/char/ava
   hash: 'a1b2c3d4e5f6',             // content hash (cache busting)
   generator: 'tools/fetch-assets.mjs',
   stats: { files, bytes, chars, charsWithBack, enemies, enemiesWithSpine, tokens, tokensWithSpine,
-           spineModels, bonds, items, bands, skills, ui, sfxUnits },
+           spineModels, bonds, items, bands, skills, ui, sfxUnits, voiceChars },
   chars:   { [charId]: { avatar, avatarE2?, portrait, portraitE2?, spine: { front: Spine, back?: Spine } } },
   enemies: { [enemyId]: { icon, spine?: Spine, spineAliasOf?: enemyId,
                           spineLocal?: { group, skel, atlas, textures, …Spine } } },
@@ -161,6 +166,14 @@ All paths are URL paths relative to the site root, for example `/assets/char/ava
              // `bgmEvent = corrosion` (卡西米尔 act13d5d0), so the rescue phase does not reuse the 作战's track
              // (audio.js bgmKeyFor 'unite', falling back to `bgm.combat` for a manifest that lacks it)
     bossBgm: { [bossId]: { intro?, loop } },                   // per-boss track of its R14/R15 level
+    voice:   { [charId]: { start, faceEnemy, select, place, skill1…skill4,
+                           resultFour, resultThree, resultTwo, resultLose } },
+                           // 干员战斗语音: an operator's official battle lines (charword_table.json placeType → slot,
+                           // tools/assets/audio.mjs VOICE_SLOTS); a slot with several lines is an array and the client
+                           // draws one (public/js/audio.js voice). Only these twelve ever play (DESIGN §21.30): the
+                           // prep-only slots 干员报到 / 编入队伍 / 任命队长 are left out of the plan by default —
+                           // nothing requests them and they cost 360 files (19.3 MB) per run — and `--voice-all` adds
+                           // them (audio.mjs VOICE_PREP_SLOTS) for the complete official set
     sfx: {
       ui:     { click, back, confirm, tab, pick, drop, error, buy, sell, income, refresh, freeze, levelup,
                 merge, equip, itemMerge, bondUp, artPlace, ready, timer, draft, yourTurn, yourTurnCircle,