feat: 亞絲娜與直葉的角色包 (#6, #7)

build_pack.py 產生對白索引（放在使用者資料目錄）；render_skill.py 把人格卡渲染成
角色 skill 並檢查精選對白逐字來自索引；插件改成執行期從資料目錄讀索引。

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

plugins/anime-companion/hooks/index-loader.ts

@@ -0,0 +1,46 @@
+import { MAX_LINE } from './examples'
+import type { IndexEntry } from './retrieval'
+import { isFunctionTag } from './tags'
+
+const DEFAULT_DIR = '.claude/anime-companion'
+
+// 對白索引由建置流水線產生，放在使用者資料目錄（不在插件裡、不入版本控制）。
+// dataDir 留空時用 ~/.claude/anime-companion；找不到家目錄就回傳 null。
+export function indexPath(dataDir: string, home: string | undefined, code: string): string | null {
+  const base = dataDir.trim() !== '' ? dataDir.trim() : home ? `${home}/${DEFAULT_DIR}` : null
+  return base === null ? null : `${base.replace(/\/+$/, '')}/${code}/index.jsonl`
+}
+
+// 一行一筆；格式不對的行略過，不讓壞掉的資料擋住載入。
+export function parseIndex(text: string): IndexEntry[] {
+  const out: IndexEntry[] = []
+  for (const line of text.split('\n')) {
+    if (line.trim() === '') continue
+    try {
+      const e = JSON.parse(line) as Record<string, unknown>
+      if (
+        typeof e.id === 'string' &&
+        isFunctionTag(e.function) &&
+        typeof e.emotion === 'string' &&
+        (e.mode === null || typeof e.mode === 'string') &&
+        typeof e.text === 'string' &&
+        e.text.length > 0 &&
+        e.text.length <= MAX_LINE
+      ) {
+        out.push({ id: e.id, function: e.function, emotion: e.emotion, mode: e.mode, text: e.text })
+      }
+    } catch {
+      // 略過壞行
+    }
+  }
+  return out
+}
+
+export async function loadIndex(read: (path: string) => Promise<string>, path: string | null): Promise<IndexEntry[]> {
+  if (path === null) return []
+  try {
+    return parseIndex(await read(path))
+  } catch {
+    return []
+  }
+}