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/http.ts

@@ -0,0 +1,92 @@
+import { redactText } from "../rss/redact";
+import type { SiteRateLimiter } from "./rate-limit";
+import { SiteError } from "./types";
+
+export interface SiteHttpContext {
+  siteId: string;
+  fetch: typeof globalThis.fetch;
+  limiter: SiteRateLimiter;
+  timeoutMs: number;
+  userAgent?: string;
+  now: () => Date;
+}
+
+function retryAfterMs(res: Response, now: Date): number | undefined {
+  const v = res.headers.get("retry-after");
+  if (!v) return undefined;
+  if (/^\d+$/.test(v.trim())) return Number(v.trim()) * 1000;
+  const t = Date.parse(v);
+  return Number.isNaN(t) ? undefined : Math.max(0, t - now.getTime());
+}
+
+/**
+ * 站点请求:先取站点令牌,再发请求;429/503 统一映射并顺延限流器。
+ * 返回的 Response 由调用方消费。错误消息只含脱敏后的 URL。
+ */
+export async function siteFetch(
+  ctx: SiteHttpContext,
+  url: string,
+  init: RequestInit & { signal?: AbortSignal } = {},
+): Promise<Response> {
+  await ctx.limiter.acquire(init.signal ?? undefined);
+  const timeout = AbortSignal.timeout(ctx.timeoutMs);
+  const signal = init.signal ? AbortSignal.any([init.signal, timeout]) : timeout;
+  const headers = new Headers(init.headers);
+  if (ctx.userAgent && !headers.has("user-agent")) headers.set("user-agent", ctx.userAgent);
+  const safeUrl = redactText(url);
+  let res: Response;
+  try {
+    res = await ctx.fetch(url, { ...init, headers, signal });
+  } catch (e) {
+    if (init.signal?.aborted) throw e;
+    const reason = timeout.aborted ? "超时" : (e as Error).message;
+    throw new SiteError(ctx.siteId, "network", redactText(`请求 ${safeUrl} 失败:${reason}`));
+  }
+  if (res.status === 429 || res.status === 503) {
+    const ra = retryAfterMs(res, ctx.now());
+    await res.body?.cancel().catch(() => {});
+    if (ra !== undefined) ctx.limiter.penalize(ra);
+    throw new SiteError(
+      ctx.siteId,
+      res.status === 429 ? "rate_limited" : "site_maintenance",
+      `请求 ${safeUrl} 返回 HTTP ${res.status}`,
+      { httpStatus: res.status, ...(ra !== undefined ? { retryAfterMs: ra } : {}) },
+    );
+  }
+  if (res.status >= 500) {
+    await res.body?.cancel().catch(() => {});
+    throw new SiteError(ctx.siteId, "site_maintenance", `请求 ${safeUrl} 返回 HTTP ${res.status}`, {
+      httpStatus: res.status,
+    });
+  }
+  return res;
+}
+
+/** 读取响应体并限制大小(默认 16 MiB,足够容纳 .torrent 与列表页)。 */
+export async function readBody(ctx: SiteHttpContext, res: Response, maxBytes = 16 * 1024 * 1024): Promise<Uint8Array> {
+  if (!res.body) return new Uint8Array();
+  const reader = res.body.getReader();
+  const chunks: Uint8Array[] = [];
+  let total = 0;
+  for (;;) {
+    const { done, value } = await reader.read();
+    if (done) break;
+    total += value.byteLength;
+    if (total > maxBytes) {
+      await reader.cancel().catch(() => {});
+      throw new SiteError(ctx.siteId, "parse_error", `响应超过 ${maxBytes} 字节上限`);
+    }
+    chunks.push(value);
+  }
+  const out = new Uint8Array(total);
+  let off = 0;
+  for (const c of chunks) {
+    out.set(c, off);
+    off += c.byteLength;
+  }
+  return out;
+}
+
+export async function readText(ctx: SiteHttpContext, res: Response): Promise<string> {
+  return new TextDecoder("utf-8").decode(await readBody(ctx, res));
+}