feat(adapters): qBittorrent, filesystem, TMDB and Emby adapters with testkit mocks (W1-3a)

- qbittorrent: WebUI API v2 client (cookie/API-key auth, add/info/files/filePrio,
  pause/resume with 5.x stop/start fallback, tags, delete with explicit deleteFiles,
  maindata), error classes, idempotent submit with local infohash (own bencode)
  and post-timeout hash/probe-tag lookup; state mapping per MoviePilot
- fs: copyWithVerify (tmp + fsync + size/sha256/sample + no-clobber commit),
  moveSafe (EXDEV surfaced), resumable crossDeviceMove, statSafe/checkRoot with
  root sentinel, budgeted incremental scan with cursor, ffprobe, statfs usage
- tmdb: multi-language search/details/seasons, LRU+TTL cache with coalescing,
  rate-limit backoff, MoviePilot match chain (name normalization, year +-1)
- emby: Emby/Jellyfin items/seasons/episodes/MediaSources, failures -> unknown
- testkit: mock qB / TMDB / Emby servers, torrent builder, temp-tree fixtures
- docs: W1-3a porting table appended to downloader-and-sites ledger

Co-Authored-By: Claude Fable 5.1 <[email protected]>

packages/testkit/src/fs/index.ts

@@ -0,0 +1 @@
+export * from "./temp-tree";

packages/testkit/src/fs/temp-tree.ts

@@ -0,0 +1,60 @@
+import { randomBytes } from "node:crypto";
+import { existsSync, statSync } from "node:fs";
+import { mkdir, mkdtemp, rm, writeFile } from "node:fs/promises";
+import { tmpdir } from "node:os";
+import { dirname, join } from "node:path";
+
+export interface TempTree {
+  root: string;
+  /** 根目录下的绝对路径 */
+  path(rel: string): string;
+  /** 写文件(自动建父目录);content 为数字时写入该长度的随机字节 */
+  write(rel: string, content: string | Buffer | number): Promise<string>;
+  cleanup(): Promise<void>;
+}
+
+/**
+ * 临时目录夹具。spec 的 key 为相对路径(以 / 结尾表示目录),value 同 write。
+ * sentinel 为真时写入库根哨兵 .uhd-root。
+ */
+export async function createTempTree(
+  spec: Record<string, string | Buffer | number | null> = {},
+  opts: { base?: string; sentinel?: boolean | string; prefix?: string } = {},
+): Promise<TempTree> {
+  const root = await mkdtemp(join(opts.base ?? tmpdir(), opts.prefix ?? "umt-fs-"));
+  const tree: TempTree = {
+    root,
+    path: (rel) => join(root, rel),
+    write: async (rel, content) => {
+      const p = join(root, rel);
+      await mkdir(dirname(p), { recursive: true });
+      await writeFile(p, typeof content === "number" ? randomBytes(content) : content);
+      return p;
+    },
+    cleanup: () => rm(root, { recursive: true, force: true }),
+  };
+  if (opts.sentinel) {
+    await writeFile(join(root, typeof opts.sentinel === "string" ? opts.sentinel : ".uhd-root"), "sentinel\n");
+  }
+  for (const [rel, v] of Object.entries(spec)) {
+    if (rel.endsWith("/") || v === null) await mkdir(join(root, rel), { recursive: true });
+    else await tree.write(rel, v);
+  }
+  return tree;
+}
+
+/**
+ * 找一个与 os.tmpdir() 不在同一设备上的可写目录(优先 /dev/shm),用于 EXDEV 测试。
+ * 找不到返回 null,测试应 skip 并注明。
+ */
+export function findCrossDeviceBase(candidates = ["/dev/shm", "/run/user", "/var/tmp"]): string | null {
+  const baseDev = statSync(tmpdir()).dev;
+  for (const c of candidates) {
+    try {
+      if (existsSync(c) && statSync(c).dev !== baseDev) return c;
+    } catch {
+      // ignore
+    }
+  }
+  return null;
+}