feat: 诊断（任务书 18 第一块）：诊断数学、四种提交、一次运行跑多个实验、账本与材料、flow 诊断各步

消融默认关，关掉时解释阶段一并跳过；选诊断实验用信息价值减成本。
eval/diagnosis/research.json 为第三块配置。vocab 字段说明的出口文字随提示词一起改，见下一次提交的 prompts/ 与同文件改动（本次含在内）。

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

tests/ledger-store.test.ts

@@ -438,6 +438,16 @@ test("关掉再打开：读出的记录不变，序号接着往下排", (t) => {
   assert.equal(reopened.append("runStarted", { run: "run1" }).seq, 9);
 });
 
+test("唯一约束：诊断结算按轮次，同一轮两次报错；同一轮的消融结算另算，不受它影响", (t) => {
+  const { ledger, path } = freshLedger(t);
+  ledger.append("diagnosisSettlement", { round: 1, result: { experiments: [] } });
+  assert.throws(() => ledger.append("diagnosisSettlement", { round: 1, result: { experiments: [] } }), /diagnosis_settlement_once/);
+  ledger.append("diagnosisSettlement", { round: 2, result: { experiments: [] } });
+  ledger.append("settlement", { round: 1, result: { cells: {} } });
+  assert.throws(() => ledger.append("diagnosisSettlement", { round: 3, run: "x", result: {} } as never), /diagnosisSettlement/);
+  assert.equal(countRows(path), 3);
+});
+
 test("打开：表结构版本不对报错；不是空文件也不是账本的库报错", (t) => {
   const dir = tempDir(t);
   const wrongVersion = join(dir, "v99.db");
@@ -446,12 +456,12 @@ test("打开：表结构版本不对报错；不是空文件也不是账本的
   db.close();
   assert.throws(() => Ledger.open(wrongVersion), /版本是 99/);
 
-  // 版本 3 是退回还没有对象字段时的账本，不迁移，打开报错。
-  const previous = join(dir, "v3.db");
-  const v3 = new DatabaseSync(previous);
-  v3.exec("PRAGMA user_version = 3");
-  v3.close();
-  assert.throws(() => Ledger.open(previous), /版本是 3.*只认版本 4/s);
+  // 版本 4 是还没有诊断结算和诊断运行用途时的账本，不迁移，打开报错。
+  const previous = join(dir, "v4.db");
+  const v4 = new DatabaseSync(previous);
+  v4.exec("PRAGMA user_version = 4");
+  v4.close();
+  assert.throws(() => Ledger.open(previous), /版本是 4.*只认版本 5/s);
 
   const foreign = join(dir, "foreign.db");
   const other = new DatabaseSync(foreign);