feat: PeopleLib 开放文献客户端，集成 Z-Library 与 LibGen 等多源检索

Electron 桌面客户端，聚合多个开放获取文献源的搜索、详情与下载。

新增数据源：
- Z-Library：邮箱登录（凭据本地存储），会话失效自动重登
- LibGen：适配新版 libgen.ac 前端（旧版 search.php 镜像已全部下线）
- Memory of the World、Sci-Hub、Anna's Archive

基础设施：
- mirror.js：镜像故障转移，支持串行优先与并发竞速两种策略，
  失效镜像 5 分钟冷却后自动重试，避免站点恢复后被永久跳过
- http.js：统一 15 秒请求超时，防止单个卡死镜像拖垮整次搜索
- settings.js：全局代理配置持久化，经 Electron net.fetch 生效于所有请求

Co-authored-by: factory-droid[bot] <138933559+factory-droid[bot]@users.noreply.github.com>

src/sources/biorxiv.js

@@ -0,0 +1,84 @@
+const { fetchJson, clampPage } = require('./http');
+
+const PAGE_SIZE = 30;
+
+function toItem(r, server) {
+  const authors = String(r.authors || '').split(';').map((s) => s.trim()).filter(Boolean).slice(0, 3).join(', ');
+  return {
+    postId: r.doi,
+    title: r.title || '(无标题)',
+    cover: '',
+    date: r.date || '',
+    url: `https://www.${server}.org/content/${r.doi}v${r.version || 1}`,
+    subtitle: [authors, r.category].filter(Boolean).join(' · '),
+    _server: server
+  };
+}
+
+function dateStr(d) { return d.toISOString().slice(0, 10); }
+
+async function fetchWindow(server, from, to, cursor, tries = 3) {
+  let last;
+  for (let i = 0; i < tries; i++) {
+    try {
+      const j = await fetchJson(`https://api.biorxiv.org/details/${server}/${from}/${to}/${cursor}`);
+      const total = parseInt(j.messages && j.messages[0] && j.messages[0].total, 10) || 0;
+      return { total, collection: j.collection || [] };
+    } catch (e) {
+      last = e;
+      if (!/504|502|503/.test(e.message)) throw e;
+      await new Promise((r) => setTimeout(r, 1500 * (i + 1)));
+    }
+  }
+  throw last;
+}
+
+module.exports = {
+  id: 'biorxiv',
+  name: 'bioRxiv 预印本',
+  supportsSearch: false,
+
+  async list(page) {
+    page = clampPage(page);
+    const server = 'biorxiv';
+    const end = new Date();
+    const daysPerPage = 3;
+    const startIdx = (page - 1) * daysPerPage;
+    const from = new Date(end.getTime() - (startIdx + daysPerPage) * 864e5);
+    const to = new Date(end.getTime() - startIdx * 864e5);
+    const { collection } = await fetchWindow(server, dateStr(from), dateStr(to), 0);
+    const items = collection.slice(0, PAGE_SIZE).map((r) => toItem(r, server));
+    return { items, maxPage: 1000, page };
+  },
+
+  async search() {
+    throw new Error('bioRxiv 暂不支持搜索，请翻页浏览');
+  },
+
+  async detail(postId) {
+    const j = await fetchJson(`https://api.biorxiv.org/details/biorxiv/${postId}`);
+    const c = (j.collection || [])[0];
+    if (!c) throw new Error('未找到该预印本');
+    return {
+      postId,
+      title: c.title,
+      cover: '',
+      authors: String(c.authors || '').split(';').map((s) => s.trim()).filter(Boolean),
+      date: c.date || '',
+      tags: [c.category ? `分类：${c.category}` : '', c.license ? `许可：${c.license}` : ''].filter(Boolean),
+      brief: c.abstract || '',
+      url: `https://www.biorxiv.org/content/${c.doi}v${c.version || 1}`,
+      links: [{ name: 'bioRxiv 页', url: `https://www.biorxiv.org/content/${c.doi}v${c.version || 1}` }]
+    };
+  },
+
+  async download(postId) {
+    const j = await fetchJson(`https://api.biorxiv.org/details/biorxiv/${postId}`);
+    const c = (j.collection || [])[0];
+    const v = (c && c.version) || 1;
+    return {
+      files: [{ name: `${String(postId).replace(/\//g, '_')}.pdf`, link: `https://www.biorxiv.org/content/${postId}v${v}.full.pdf`, format: 'PDF' }],
+      links: [{ name: 'bioRxiv 页', url: `https://www.biorxiv.org/content/${postId}v${v}` }]
+    };
+  }
+};