feat: 账本 ledger 模块（任务书 03）

一张只追加的表（序号、种类、内容、哈希），禁改禁删两条触发器。
有自己编号、只发生一次的 8 种记录加部分唯一索引，重复就报错：阶段开、阶段关、运行登记、
确认启动（确认没启动的结果也算这一条，防止同一次运行既扣次又退还）、运行结果、模型调用开始、结束、消融结算。
写入时只查四种拒收：只收开着的阶段的提交；替换必须接本人同一阶段、同一对象、同一种提交的最新一版，实现与核验类不能替换；
结果先于确认启动（没启动除外）；本轮消融已有格启动后不能关解释阶段。
写提案时作者自评拆成封存。提供打开（核对表结构版本，非账本库不改动）、追加、同步事务、读取、未完成的动作。
第一版的可见性、截止序号、通用唯一键、jev 记录和多余的前提检查已按新版任务书清掉。
三轮全新上下文审阅；flow 传错参数一类的意见按 CLAUDE.md"罕见情况怎么办"第 2 条只记录不加代码。

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

tests/ledger-helpers.ts

@@ -0,0 +1,103 @@
+import { mkdtempSync, rmSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import type { TestContext } from "node:test";
+import { Ledger } from "../src/ledger/index.ts";
+import type { ModelUsage, ProcessResult, Range, RunDefinition, Stage, Submission } from "../src/vocab/index.ts";
+
+// ledger 测试共用：每个测试在自己的临时目录里建一个真实的数据库文件，测试结束时连目录一起删掉。
+
+export function tempDir(t: TestContext): string {
+  const dir = mkdtempSync(join(tmpdir(), "inforsi-ledger-"));
+  t.after(() => rmSync(dir, { recursive: true, force: true }));
+  return dir;
+}
+
+export function freshLedger(t: TestContext): { ledger: Ledger; path: string } {
+  const path = join(tempDir(t), "ledger.db");
+  const ledger = Ledger.open(path);
+  t.after(() => ledger.close());
+  return { ledger, path };
+}
+
+export const range = (q1: number, q5: number, q9: number): Range => ({ q1, q5, q9 });
+
+export function proposal(estimate: Range, body = "提案正文"): Submission<"proposal"> {
+  return {
+    factors: [{ name: "换优化器", method: "把 SGD 换成 Adam", keySettings: "学习率 0.01", continues: null }],
+    safeguards: [],
+    metrics: { defined: [], reused: [] },
+    authorEstimate: estimate,
+    body,
+  };
+}
+
+export const prediction = (r: Range): Submission<"firstPrediction"> => ({ range: r, body: "理由" });
+export const critique = (body = "挑刺内容"): Submission<"critique"> => ({ target: "whole", body });
+export const wrapUp = (body = "收尾"): Submission<"wrapUp"> => ({ body });
+
+export const implementation = (body = "无"): Submission<"implementation"> => ({
+  factorLocations: [{ factor: "p1", locations: ["solve.py:10-20"] }],
+  safeguardLocations: [],
+  unassigned: [],
+  concerns: "无",
+  body,
+});
+
+export const definition: RunDefinition = {
+  command: ["python", "solve.py"],
+  workdir: "/work",
+  image: { digest: `sha256:${"0".repeat(64)}`, runtime: "runc" },
+  wallSeconds: 120,
+  cores: 1,
+  inheritEnv: false,
+  env: {},
+};
+
+export const exited: ProcessResult = {
+  ending: "exited",
+  exitCode: 0,
+  cpuSeconds: { status: "measured", value: 100 },
+  wallSeconds: { status: "measured", value: 101 },
+  peakMemoryBytes: { status: "measured", value: 1e8 },
+};
+
+export const notStarted: ProcessResult = { ending: "notStarted", reason: "启动前取消" };
+
+/** 开一个阶段，返回开阶段那条记录的序号。 */
+export function openStage(
+  ledger: Ledger,
+  stageId: string,
+  stage: Stage,
+  round: number,
+  roster: string[] = ["r1", "r2"],
+): number {
+  return ledger.append("stageOpen", { stageId, stage, round, roster }).seq;
+}
+
+export function closeStage(ledger: Ledger, stageId: string): number {
+  return ledger.append("stageClose", { stageId }).seq;
+}
+
+/** 登记一次运行。 */
+export function planRun(ledger: Ledger, run: string, purpose: "baseline" | "forward" | "ablation", round: number): number {
+  return ledger.append("runPlanned", { run, purpose, round, object: purpose === "baseline" ? null : `obj-${run}`, definition }).seq;
+}
+
+/** 一次模型调用的开始记录，materials 是这次任务的全部材料。 */
+export const callStart = (call: string, actor = "r1", stageId: string | null = null) => ({
+  call,
+  actor,
+  stageId,
+  model: "glm-5.3",
+  materials: { firstMessage: "任务说明……", tools: ["read", "submit"] },
+});
+
+const unknownCount = { status: "unmeasured" as const, reason: "服务没报" };
+export const usage: ModelUsage = {
+  inputTokens: unknownCount,
+  cacheReadTokens: unknownCount,
+  cacheWriteTokens: unknownCount,
+  outputTokens: unknownCount,
+  cost: unknownCount,
+};