feat: 友链/书库/移动端导航/排行榜等多模块功能

新增模块：
- 友链（friendlink）后端处理 + 前端管理页与友链板
- 书库（library）：导入、章节、封面、阅读页、横竖版自适应 AdaptiveCoverSlot
- 顶栏导航（header_nav）配置与 MobileTabBar/MobileRailDrawers 移动端抽屉
- 排行榜 service 测试、站点页面测试、时间线发布（timeline_release）

其它改动：
- 后端 handlers/services 全量小幅调整
- 前端组件、库函数、URL/品牌/站点 URL 工具更新
- Lightbox 图片、MdEntries 条目卡、coverColor 派生色相等前端能力

frontend/app/links/page.tsx

@@ -0,0 +1,86 @@
+import type { Metadata } from "next";
+import { cookies } from "next/headers";
+import { fetchFriendLinks, fetchSiteState, type FriendLink } from "@/lib/api";
+import { authCookieHeader } from "@/lib/cookies";
+import { brandAliasPath } from "@/lib/brand";
+import { getMeCached, getPublicSettingsCached } from "@/lib/serverData";
+import { isAdminOrAbove } from "@/lib/roles";
+import { requestCanonical } from "@/lib/canonicalMeta";
+import { resolveSiteOrigin } from "@/lib/siteUrl";
+import LinksBoard from "./LinksBoard";
+
+export async function generateMetadata(): Promise<Metadata> {
+  return {
+    title: "友情链接",
+    description: "本站友情链接收录与申请",
+    ...(await requestCanonical("/links")),
+  };
+}
+
+export default async function FriendLinksPage() {
+  const cookie = authCookieHeader(await cookies());
+  let links: FriendLink[] = [];
+  let error = "";
+  try {
+    const res = await fetchFriendLinks(cookie || undefined);
+    links = res.links ?? [];
+  } catch (e) {
+    error = e instanceof Error ? e.message : "加载友情链接失败";
+  }
+
+  const [settings, siteState, me] = await Promise.all([
+    getPublicSettingsCached(),
+    fetchSiteState(),
+    getMeCached(cookie || undefined),
+  ]);
+  const isLoggedIn = !!me.user;
+  const canManage = !!me.user && isAdminOrAbove(me.user.role);
+  // 站点 LOGO 用固定对外地址（换图不变链，对方收藏的地址永不失效），补全为绝对地址供申请人直接复制
+  const siteBase = siteState.site_url?.trim() || resolveSiteOrigin() || "";
+  const logoAlias = settings.logo_light_url
+    ? brandAliasPath("logo_light")
+    : settings.favicon_url
+      ? brandAliasPath("favicon")
+      : "";
+  const siteLogo = logoAlias && siteBase ? new URL(logoAlias, siteBase).toString() : "";
+
+  return (
+    <div className="mx-auto w-full max-w-[1200px] px-4 sm:px-6 py-8">
+      {/* 标题 + 申请须知 */}
+      <header className="text-center">
+        <h1
+          className="text-[26px] sm:text-[30px] font-extrabold tracking-tight inline-flex flex-col items-center"
+          style={{ color: "var(--ink)" }}
+        >
+          友情链接
+          <span
+            className="mt-1.5 h-[3px] w-10 rounded-full"
+            style={{ background: "var(--accent)" }}
+            aria-hidden
+          />
+        </h1>
+      </header>
+
+      {/* 搜索 + 卡片墙 + 我的申请 + 申请弹窗 */}
+      <div className="mt-5">
+        {error ? (
+          <p
+            className="rounded-lg px-3 py-2 text-[13px] text-center"
+            style={{ background: "var(--panel-2)", color: "var(--ink)", border: "1px solid var(--line)" }}
+          >
+            {error}
+          </p>
+        ) : (
+          <LinksBoard
+            links={links}
+            isLoggedIn={isLoggedIn}
+            canManage={canManage}
+            siteName={settings.site_name}
+            siteUrl={siteState.site_url}
+            siteLogo={siteLogo}
+          />
+        )}
+      </div>
+    </div>
+  );
+}