feat(downloads): 多下载器路由:默认下载器、站点指定下载器、别名

照 MP(chain/download/submission.py:明确指定 or 站点下载器 or 默认):
- 迁移 0063:downloader_instance.is_default(至多一个,唯一索引)、site.downloader_instance_id
- pickInstance:明确指定 > 站点指定 > 默认 > 第一个可用;自动下载(gates)与手动下载共用
- 设置:下载器名称改称别名,新增「设为默认下载器」;站点编辑新增「下载器」选择
- 测试 downloader-routing.test.ts

Co-Authored-By: Claude Opus 5.5 <[email protected]>

apps/server/test/acquisition-organize/downloader-routing.test.ts

@@ -0,0 +1,63 @@
+import { afterAll, beforeAll, describe, expect, it } from "vitest";
+import { loadInstances, pickInstance } from "../../src/modules/acquisition-organize/services/common.ts";
+import { createHarness, type Harness, pgAvailable, seedBase } from "./harness.ts";
+
+const hasPg = await pgAvailable();
+
+// 多下载器路由(照 MP):明确指定 > 站点指定 > 默认 > 第一个可用
+describe.skipIf(!hasPg)("下载器选择", () => {
+  let h: Harness;
+  let first: string;
+  let anime: string;
+  let siteId: string;
+
+  beforeAll(async () => {
+    h = await createHarness("downloader_routing");
+    const base = await seedBase(h.db, {
+      libraryPath: "/tmp/lib",
+      cachePath: "/tmp/cache",
+      qbUrl: "http://127.0.0.1:9",
+    });
+    first = base.instanceId;
+    siteId = base.siteId;
+    const add = async (name: string) =>
+      (
+        await h.db
+          .insertInto("downloader_instance")
+          .values({ name, base_url: "http://127.0.0.1:9", settings: JSON.stringify({ savePath: "/tmp/cache" }) })
+          .returning("id")
+          .executeTakeFirstOrThrow()
+      ).id;
+    anime = await add("zz-番剧专用");
+  });
+  afterAll(async () => {
+    await h?.close();
+  });
+
+  const pick = async (opts: Parameters<typeof pickInstance>[2]) =>
+    (await pickInstance(h.db, await loadInstances(h.db), opts))?.inst.id;
+
+  it("都没指定:第一个可用;设了默认后用默认", async () => {
+    expect(await pick({})).toBe(first);
+    await h.db.updateTable("downloader_instance").set({ is_default: true }).where("id", "=", anime).execute();
+    expect(await pick({ siteId })).toBe(anime);
+  });
+
+  it("站点指定优先于默认;明确指定优先于站点", async () => {
+    await h.db.updateTable("site").set({ downloader_instance_id: first }).where("id", "=", siteId).execute();
+    expect(await pick({ siteId })).toBe(first);
+    expect(await pick({ siteId, explicitId: anime })).toBe(anime);
+  });
+
+  it("站点指定的下载器停用时回落默认;明确指定的不可用时不悄悄换", async () => {
+    await h.db.updateTable("downloader_instance").set({ enabled: false }).where("id", "=", first).execute();
+    expect(await pick({ siteId })).toBe(anime);
+    expect(await pick({ explicitId: first })).toBeUndefined();
+  });
+
+  it("默认下载器至多一个", async () => {
+    await expect(
+      h.db.updateTable("downloader_instance").set({ is_default: true }).where("id", "=", first).execute(),
+    ).rejects.toThrow();
+  });
+});