fix: 采集失败不降级有数据分行+任务领取计数对齐实际分发行数

- 采集失败时按 latest_likes 分流：无数据才标 failed，已有历史数据保持
  success 并注明沿用上次数据，collection_updated_at 不动；run 行照实记失败
- 种子 seedIfEmpty 末尾统一对账 claimed_quantity，杜绝演示数据口径漂移
- 新增 mysql/0021 对账迁移，修复 0020 物理合并遗留的生产计数漂移
- 运营端展示全面改读实时 dist_total（任务卡双面板/项目树/概览/进度），
  project-service 查询补 dist_total 子查询
- 走查实证：卡片 7/18 vs 详情已领取 2 两处口径打架；保存采集计划补采
  失败会把历史成功行改写为 failed

tests/claimed-quantity.test.mjs

@@ -0,0 +1,53 @@
+import assert from "node:assert/strict";
+import { readFile } from "node:fs/promises";
+import test from "node:test";
+
+// claimed_quantity 口径：领取(+1)/释放(-1) 维护的不变式是
+// claimed_quantity == 当前分发行数。种子与 0020 迁移都可能造成漂移，
+// 这里钉住三道防线：种子末尾对账、0021 生产对账、UI 一律读实时 dist_total。
+
+test("seed reconciles claimed_quantity with actual distribution rows", async () => {
+  const source = await readFile(
+    new URL("../lib/mvp-db.ts", import.meta.url),
+    "utf8",
+  );
+  const reconcile = source.indexOf(
+    "SET claimed_quantity = (\n           SELECT COUNT(*) FROM distributions d WHERE d.task_id = tasks.id",
+  );
+  assert.ok(reconcile > 0, "种子阶段缺少 claimed_quantity 对账 UPDATE");
+  const lastDistributionInsert = source.lastIndexOf(
+    "INSERT INTO distributions",
+  );
+  assert.ok(
+    reconcile > lastDistributionInsert,
+    "对账必须发生在所有分发 INSERT 之后",
+  );
+  const batchEnd = source.indexOf("await db.batch(batch);", reconcile);
+  assert.ok(batchEnd > reconcile, "对账语句必须在 seedIfEmpty 的 batch 内执行");
+});
+
+test("migration 0021 recalculates drifted claimed_quantity in production", async () => {
+  const migration = await readFile(
+    new URL("../mysql/0021_reconcile_claimed_quantity.sql", import.meta.url),
+    "utf8",
+  );
+  assert.match(migration, /UPDATE tasks\s+SET claimed_quantity = \(\s+SELECT COUNT\(\*\) FROM distributions d\s+WHERE d\.task_id = tasks\.id\s+\)/);
+  assert.match(migration, /WHERE claimed_quantity <> \(/);
+});
+
+test("admin surfaces read the live distribution count, not the counter", async () => {
+  const [adminApp, projectService] = await Promise.all([
+    readFile(new URL("../app/admin-app.tsx", import.meta.url), "utf8"),
+    readFile(new URL("../lib/project-service.ts", import.meta.url), "utf8"),
+  ]);
+
+  // 任务卡双面板 + 概览统计
+  assert.match(adminApp, /panelMetric\(task\.dist_total \?\? 0, task\.quantity, "已领取"/);
+  assert.match(adminApp, /panelMetric\(task\.dist_submitted \?\? 0, task\.dist_total \?\? 0, "已收取"/);
+  assert.match(adminApp, /sum \+ \(task\.dist_total \?\? 0\)/);
+  // 项目树明细同样用实时口径
+  assert.match(projectService, /AS dist_total/);
+  assert.match(adminApp, /\{task\.dist_total\} \/ \{task\.quantity\}/);
+  // 展示层不再读反规范化计数器
+  assert.doesNotMatch(adminApp, /task\.claimed_quantity/);
+});

tests/collection-schedule.test.mjs

@@ -1,4 +1,5 @@
 import assert from "node:assert/strict";
+import { readFile } from "node:fs/promises";
 import test from "node:test";
 import { isCollectionScheduleDue } from "../lib/collection-service.ts";
 import { sortWithNullsLast } from "../lib/sort-utils.ts";
@@ -56,3 +57,24 @@ test("sorts both directions while keeping missing values last", () => {
     ["high", "middle", "low", "missing-a", "missing-b"],
   );
 });
+
+test("a failed collection keeps historically successful rows on success", async () => {
+  const source = await readFile(
+    new URL("../lib/collection-service.ts", import.meta.url),
+    "utf8",
+  );
+
+  // 失败写入必须按 latest_likes 分流：无数据 → failed；
+  // 已有历史数据 → 保持 success，仅描述里说明沿用上次数据。
+  assert.match(
+    source,
+    /collection_status = CASE\s+WHEN latest_likes IS NULL THEN 'failed'\s+ELSE 'success'\s+END/,
+  );
+  assert.match(
+    source,
+    /ELSE \?\s+END,\s+collection_updated_at = CASE\s+WHEN latest_likes IS NULL THEN CURRENT_TIMESTAMP\s+ELSE collection_updated_at/,
+  );
+  assert.match(source, /`\$\{message\}，沿用上次采集数据`/);
+  // run 行照实记录失败，保留可观测性
+  assert.match(source, /UPDATE collection_runs\s+SET status = 'failed'/);
+});