test(selftest): 補語域的案例，735 → 745

涵蓋：第三種 kind 的檔名與標籤、自由欄位加不進去、CLI 同一支寫得進去、
--facet 給錯會列出四格、一輪最多 3 格、輪替起點可重現（同一輪兩次結果相同、
不同輪不同）、跑滿一圈四格都輪得到、注入文字講明它是加法、沒有語域檔就不注入。

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

scripts/selftest.mjs

@@ -3270,6 +3270,50 @@ console.log("\n㉜ 語氣層（voice/）：學語氣，但不准變成照抄");
     const entries = ctx.split("\n").filter((l) => l.startsWith("  - 「") || l.startsWith("遇到「"));
     return ctx.includes("學語氣，不要照抄這幾句") && entries.length <= pl.VOICE_INJECT_MAX;
   })());
+  // 語域：語氣層的**加法面**。跟原句同一個目錄、同一支 voice add，
+  // 所以 persona-story 與 persona-anime 寫的是同一格，不會各存一份
+  check("語域是第三種 voice kind，檔名與標籤都對",
+    pl.VOICE_KINDS.idiolect === "idiolect.md" && pl.VOICE_LABELS.idiolect === "語域");
+  check("四格是寫死的，自由欄位加不進去（會長出什麼都能塞的格子）",
+    pl.addVoiceIdiolect("voicey", { facet: "風格", value: "文雅" }) === null);
+  check("CLI 用同一支 voice add 寫語域", (() => {
+    const res = cli(["voice", "add", "--session", S_V, "--kind", "idiolect", "--facet", "自稱", "--value", "我"]);
+    return res.status === 0 && fs.existsSync(pl.voicePath("voicey", "idiolect")) &&
+      pl.loadVoice("voicey").idiolect.some((r) => r.facet === "自稱" && r.value === "我");
+  })(), JSON.stringify(pl.loadVoice("voicey").idiolect));
+  check("--facet 給錯會被擋，而且把四格列出來", (() => {
+    const res = cli(["voice", "add", "--session", S_V, "--kind", "idiolect",
+      "--facet", "語氣", "--value", "軟"], { expectOk: false });
+    return res.status !== 0 && pl.IDIOLECT_FACETS.every((f) => String(res.stderr).includes(f));
+  })());
+  for (const [facet, value] of [["句尾", "⋯吧"], ["口癖", "算了"], ["不說", "絕對"]]) {
+    cli(["voice", "add", "--session", S_V, "--kind", "idiolect", "--facet", facet, "--value", value]);
+  }
+  check("一輪最多注入 3 格（四格輪替，不是一次全塞）", (() => {
+    const brief = pl.idiolectBrief("voicey", { turn: 0 });
+    const parts = brief.split("：")[1].split("。")[0].split("；");
+    return parts.length === pl.IDIOLECT_INJECT_MAX && brief.includes("下一輪輪到");
+  })(), pl.idiolectBrief("voicey", { turn: 0 }));
+  check("輪替起點由第幾輪算出來，不用隨機數（同一輪重跑結果一樣）", (() => {
+    const a = pl.idiolectBrief("voicey", { turn: 0 });
+    const b = pl.idiolectBrief("voicey", { turn: 0 });
+    const c = pl.idiolectBrief("voicey", { turn: 1 });
+    return a === b && a !== c;
+  })());
+  check("四格都輪得到（跑滿一圈每格至少出現一次）", (() => {
+    const seen = new Set();
+    for (let t = 0; t < pl.IDIOLECT_FACETS.length; t += 1) {
+      const brief = pl.idiolectBrief("voicey", { turn: t });
+      for (const f of pl.IDIOLECT_FACETS) if (brief.includes(`${f}→`)) seen.add(f);
+    }
+    return seen.size === pl.IDIOLECT_FACETS.length;
+  })(), JSON.stringify(pl.IDIOLECT_FACETS.map((f, t) => pl.idiolectBrief("voicey", { turn: t }).slice(0, 60))));
+  check("語域講明它是加法（黑名單刪 AI 腔，這幾格補他自己的講法）", (() => {
+    const brief = pl.idiolectBrief("voicey");
+    return brief.includes("加法") && brief.includes("認得出是誰");
+  })(), pl.idiolectBrief("voicey"));
+  check("turnContext 帶得到語域", pl.turnContext("voicey", S_V, "你自己怎麼說").includes("語域（這一輪"));
+  check("沒有語域檔的人格不注入這段", pl.idiolectBrief("calmsplit") === "");
   // voice/ 會被 `sync pull`／`import` 覆蓋 → 它是外部輸入，讀取端要自己中和
   check("語氣檔裡的注入標記讀進來就被中和（它是會被 sync pull 覆蓋的檔）", (() => {
     fs.appendFileSync(pl.voicePath("voicey", "sample"),