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.

tools/assets/cache.mjs

@@ -1,6 +1,7 @@
 // Cached upstream JSON indexes needed by the asset pipeline:
-//   .cache/gamedata/excel/audio_data.json  (Kengxxiao/ArknightsGameData, zh_CN)
-//   .cache/ark-models/models_data.json      (isHarryh/Ark-Models enemy Spine index)
+//   .cache/gamedata/excel/audio_data.json     (Kengxxiao/ArknightsGameData, zh_CN)
+//   .cache/gamedata/excel/charword_table.json (same repo: the operators' voice slots and voice assets)
+//   .cache/ark-models/models_data.json        (isHarryh/Ark-Models enemy Spine index)
 // Downloaded once when missing (or with --refresh-index), then reused.
 
 import { mkdir, readFile, rename, writeFile } from 'node:fs/promises';
@@ -46,10 +47,10 @@ export async function cachedJson({ cacheFile, url, refresh = false, offline = fa
 }
 
 /**
- * Load audio_data.json (official) and Ark-Models models_data.json.
+ * Load audio_data.json (official), charword_table.json (official voice slots) and Ark-Models models_data.json.
  * @param {string} root project root
  * @param {{refresh?:boolean, offline?:boolean, log?:(m:string)=>void}} [opts]
- * @returns {Promise<{ audioData: any, modelsData: any }>}
+ * @returns {Promise<{ audioData: any, modelsData: any, charword: any }>}
  */
 export async function loadIndexes(root, opts = {}) {
   const audioData = await cachedJson({
@@ -59,6 +60,15 @@ export async function loadIndexes(root, opts = {}) {
     offline: opts.offline,
     log: opts.log,
   });
+  // 11 MB, and raw.githubusercontent stalls on it often: the jsDelivr mirror cachedJson() falls back to is the
+  // reliable path (the operator battle voice needs it, plan.mjs indexVoice).
+  const charword = await cachedJson({
+    cacheFile: join(root, '.cache', 'gamedata', 'excel', 'charword_table.json'),
+    url: RAW.gamedata + 'excel/charword_table.json',
+    refresh: opts.refresh,
+    offline: opts.offline,
+    log: opts.log,
+  });
   const modelsData = await cachedJson({
     cacheFile: join(root, '.cache', 'ark-models', 'models_data.json'),
     url: RAW.arkModels + 'models_data.json',
@@ -66,5 +76,5 @@ export async function loadIndexes(root, opts = {}) {
     offline: opts.offline,
     log: opts.log,
   });
-  return { audioData, modelsData };
+  return { audioData, modelsData, charword };
 }