feat: 站点访问统计与可配置侧边栏组件

- 新增访问统计：visitstats 服务与查询、visit_capture 中间件、爬虫/来源识别、管理端 analytics 页面
- 新增侧边栏：sidebar 服务与 handler、管理端 sidebar 配置页、前端侧边栏组件
- 新增 widget 嵌入代码生成（widgetCode）与 widgetApi
- 遥测逻辑迁移至 handler 层，删除 service/telemetry
- env 示例补充 Docker 部署可信代理 IP 说明

frontend/components/sidebar/registry.tsx

@@ -0,0 +1,155 @@
+import type {
+  ActiveUser,
+  AnnouncementSummary,
+  Board,
+  BoardModerator,
+  BoardSidebarStats,
+  BoardWithCount,
+  CheckinStatus,
+  NewUser,
+  OverviewStats,
+  PostListItem,
+  PublicAdItem,
+  PublicSponsorItem,
+  SidebarPageItem,
+  User,
+  UserProfile,
+} from "@/lib/api";
+import PostToc, { type TocItem } from "@/components/PostToc";
+import { WorkspaceNavPanel } from "@/components/home/WorkspaceNav";
+import {
+  PulseCard,
+  Announcements,
+  AdsPanel,
+  SponsorsPanel,
+  HotRanking,
+  NewUsers,
+  ActiveUsers,
+  FriendLinks,
+  AboutSite,
+} from "@/components/home/CommunityPanels";
+import {
+  Moderators,
+  BoardIntro,
+  BoardPulse,
+  BoardHot,
+  BoardActive,
+} from "@/components/home/BoardPanels";
+import {
+  BoardCard as PostBoardCard,
+  AuthorRailCard as PostAuthorCard,
+  AuthorPosts as PostAuthorPosts,
+} from "@/components/post/PostRailBlocks";
+
+// 侧栏块 props 汇总：页面把已有数据整包传入，块按需取用；
+// 某块所需数据缺失（如板块态没传 stats）时对应块渲染为空，安全跳过。
+export interface SidebarBlockProps {
+  allowComments: boolean;
+  user?: User | null;
+  checkin?: CheckinStatus | null;
+
+  // home 范围
+  boards?: BoardWithCount[];
+  stats?: OverviewStats;
+  announcements?: AnnouncementSummary[];
+  canManageAnnouncements?: boolean;
+  ads?: PublicAdItem[];
+  adsPanelTitle?: string;
+  adsEnabled?: boolean;
+  sponsors?: PublicSponsorItem[];
+  sponsorsPanelTitle?: string;
+  sponsorsEnabled?: boolean;
+  hot?: PostListItem[];
+  newUsers?: NewUser[];
+  activeUsers?: ActiveUser[];
+  sidebarPages?: SidebarPageItem[];
+  siteDescription?: string;
+  canManagePages?: boolean;
+
+  // board 范围
+  board?: BoardWithCount;
+  moderators?: BoardModerator[];
+  boardStats?: BoardSidebarStats;
+  boardHot?: PostListItem[];
+  boardActiveUsers?: ActiveUser[];
+
+  // post 范围
+  postBoard?: Board;
+  authorProfile?: UserProfile;
+  authorPosts?: PostListItem[];
+  toc?: TocItem[];
+}
+
+// 内置块注册表：key → 组件。数据未就绪或未知 key 返回 null（渲染层静默跳过）。
+export function renderSidebarBlock(key: string, p: SidebarBlockProps) {
+  switch (key) {
+    case "board_nav":
+      return p.boards ? <WorkspaceNavPanel boards={p.boards} user={p.user} /> : null;
+    case "pulse":
+      return p.stats ? (
+        <PulseCard stats={p.stats} checkin={p.checkin} allowComments={p.allowComments} />
+      ) : null;
+    case "announcements":
+      return p.announcements ? (
+        <Announcements items={p.announcements} canManageAnnouncements={p.canManageAnnouncements} />
+      ) : null;
+    case "ads":
+      return p.ads && p.adsEnabled !== false ? (
+        <AdsPanel items={p.ads} title={p.adsPanelTitle || "自助推广"} enabled />
+      ) : null;
+    case "sponsors":
+      return p.sponsors && p.sponsorsEnabled !== false ? (
+        <SponsorsPanel
+          items={p.sponsors}
+          title={p.sponsorsPanelTitle || "赞助商"}
+          enabled
+        />
+      ) : null;
+    case "hot":
+      return p.hot ? <HotRanking posts={p.hot} allowComments={p.allowComments} /> : null;
+    case "new_users":
+      return p.newUsers ? <NewUsers users={p.newUsers} /> : null;
+    case "active_users":
+      return p.activeUsers ? (
+        <ActiveUsers users={p.activeUsers} allowComments={p.allowComments} />
+      ) : null;
+    case "friend_links":
+      return <FriendLinks />;
+    case "about_site":
+      return p.sidebarPages || p.canManagePages ? (
+        <AboutSite
+          pages={p.sidebarPages ?? []}
+          siteDescription={p.siteDescription}
+          canManagePages={p.canManagePages}
+        />
+      ) : null;
+    case "board_moderators":
+      return p.moderators ? <Moderators items={p.moderators} /> : null;
+    case "board_intro":
+      return p.board ? <BoardIntro board={p.board} /> : null;
+    case "board_pulse":
+      return p.boardStats ? (
+        <BoardPulse stats={p.boardStats} checkin={p.checkin} allowComments={p.allowComments} />
+      ) : null;
+    case "board_hot":
+      return p.boardHot ? (
+        <BoardHot posts={p.boardHot} allowComments={p.allowComments} />
+      ) : null;
+    case "board_active":
+      return p.boardActiveUsers ? (
+        <BoardActive users={p.boardActiveUsers} allowComments={p.allowComments} />
+      ) : null;
+    case "post_board":
+      return p.postBoard ? <PostBoardCard board={p.postBoard} /> : null;
+    case "post_author":
+      return p.authorProfile ? (
+        <PostAuthorCard profile={p.authorProfile} allowComments={p.allowComments} />
+      ) : null;
+    case "post_author_posts":
+      return p.authorPosts ? <PostAuthorPosts posts={p.authorPosts} /> : null;
+    case "post_toc":
+      return p.toc && p.toc.length > 0 ? <PostToc items={p.toc} /> : null;
+    default:
+      return null;
+  }
+}