feat(adapters): RSS and PT site adapters ported from MoviePilot v3 + mocks (W1-3b)

- rss: port of MP RssHelper._parse_impl/get_rss_link semantics with safe
  XML (entities off, DTD/ENTITY rejected, size/item caps), ETag/Last-Modified,
  backoff + Retry-After, circuit breaker with manual reset, passkey redaction,
  overlap-window GUID+digest dedupe
- sites/spider: TS port of MP SiteSpider (indexer schema, search URL builder,
  field DSL, filters, Jinja templates via nunjucks, login-page detection);
  audiences definition hand-written as JSON; raw category id preserved;
  shared per-site token bucket
- sites/mteam: port of MP MTorrentSpider (params, result mapping, promo
  factors, genDlToken flow) without embedding the API key in enclosures;
  business code/message checks
- testkit: mock RSS server, mock NexusPHP site, mock M-Team API
- docs: W1-3b migration mapping appended to porting ledger

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

packages/adapters/src/sites/rate-limit.ts

@@ -0,0 +1,95 @@
+/**
+ * 站点级令牌桶:同一站点的列表/搜索/详情/下载(以及将来的浏览器操作)共享一个实例。
+ * 容量 burst,每 minIntervalMs 补 1 个令牌;429/Retry-After 通过 penalize 整体顺延。
+ */
+
+export interface SiteRateLimiter {
+  acquire(signal?: AbortSignal): Promise<void>;
+  /** 不等待:有令牌返回 true 并消耗 */
+  tryAcquire(): boolean;
+  /** 站点要求暂停(Retry-After 等),在 ms 内不发放令牌 */
+  penalize(ms: number): void;
+  readonly stats: { granted: number; waitedMs: number };
+}
+
+export interface RateLimiterOptions {
+  minIntervalMs: number;
+  burst?: number;
+  now?: () => number;
+  sleep?: (ms: number, signal?: AbortSignal) => Promise<void>;
+}
+
+function defaultSleep(ms: number, signal?: AbortSignal): Promise<void> {
+  return new Promise((resolve, reject) => {
+    if (signal?.aborted) {
+      reject(signal.reason);
+      return;
+    }
+    const t = setTimeout(() => {
+      signal?.removeEventListener("abort", onAbort);
+      resolve();
+    }, ms);
+    const onAbort = () => {
+      clearTimeout(t);
+      reject(signal?.reason);
+    };
+    signal?.addEventListener("abort", onAbort, { once: true });
+  });
+}
+
+export function createSiteRateLimiter(opts: RateLimiterOptions): SiteRateLimiter {
+  const interval = Math.max(0, opts.minIntervalMs);
+  const burst = Math.max(1, opts.burst ?? 1);
+  const now = opts.now ?? Date.now;
+  const sleep = opts.sleep ?? defaultSleep;
+  let tokens = burst;
+  let last = now();
+  let blockedUntil = 0;
+  let queue: Promise<void> = Promise.resolve();
+  const stats = { granted: 0, waitedMs: 0 };
+
+  const refill = () => {
+    const t = now();
+    if (interval === 0) tokens = burst;
+    else tokens = Math.min(burst, tokens + (t - last) / interval);
+    last = t;
+  };
+
+  const waitMs = (): number => {
+    refill();
+    const t = now();
+    if (t < blockedUntil) return blockedUntil - t;
+    if (tokens >= 1) return 0;
+    return Math.ceil((1 - tokens) * interval);
+  };
+
+  return {
+    stats,
+    tryAcquire() {
+      if (waitMs() > 0) return false;
+      tokens -= 1;
+      stats.granted++;
+      return true;
+    },
+    penalize(ms) {
+      blockedUntil = Math.max(blockedUntil, now() + ms);
+      tokens = Math.min(tokens, 0);
+    },
+    acquire(signal) {
+      // 串行排队,保证先到先得、不会并发抢同一个令牌
+      const run = queue.then(async () => {
+        for (;;) {
+          signal?.throwIfAborted();
+          const w = waitMs();
+          if (w <= 0) break;
+          stats.waitedMs += w;
+          await sleep(w, signal);
+        }
+        tokens -= 1;
+        stats.granted++;
+      });
+      queue = run.catch(() => {});
+      return run;
+    },
+  };
+}