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/home/WorkspaceNav.tsx

@@ -12,81 +12,95 @@ function boardHref(id: number) {
   return `/?board=${id}`;
 }
 
-// 桌面左栏：整块模块，与右栏 j13-module 对齐
-export function WorkspaceNav({ boards, user }: { boards: BoardWithCount[]; user?: User | null }) {
+// 板块目录裸面板：只有 j13-module 本体，不含外层 nav / 宽度 / sticky 类，
+// 供侧栏注册表按管理端配置在任意侧栏渲染。
+export function WorkspaceNavPanel({
+  boards,
+  user,
+}: {
+  boards: BoardWithCount[];
+  user?: User | null;
+}) {
   const params = useSearchParams();
   const activeBoard = Number(params.get("board")) || 0;
   const showAdmin = !!user && isStaff(user.role);
 
+  return (
+    <section className="j13-module flex max-h-[var(--rail-max-h)] flex-col overflow-hidden" aria-label="板块目录">
+      <p className="j13-module-title shrink-0">
+        <LayoutGrid size={15} style={{ color: "var(--accent)" }} aria-hidden />
+        板块目录
+        {boards.length > 0 ? (
+          <span className="ml-auto meta text-[11.5px] font-medium tracking-normal tabular-nums">
+            {boards.length} 个
+          </span>
+        ) : null}
+      </p>
+
+      <div className="j13-rail-scroll j13-board-list mt-2.5 min-h-0 flex-1">
+        <Link
+          href="/"
+          className="j13-bcard"
+          aria-current={activeBoard === 0 ? "page" : undefined}
+        >
+          <span
+            className="j13-bcard-ico"
+            style={{ background: "var(--accent-soft)", color: "var(--accent)" }}
+            aria-hidden="true"
+          >
+            <Home size={15} />
+          </span>
+          <span className="j13-bcard-name flex-1 truncate">全部讨论</span>
+        </Link>
+
+        {boards.length > 0 ? <div className="j13-board-split" role="separator" /> : null}
+
+        {boards.map((b) => (
+          <Link
+            key={b.id}
+            href={boardHref(b.id)}
+            className="j13-bcard"
+            aria-current={activeBoard === b.id ? "page" : undefined}
+            aria-label={`${b.name}板块，${b.post_count} 篇讨论`}
+          >
+            <span className={`av-${boardColor(b)} j13-bcard-ico`} aria-hidden="true">
+              <BoardIcon icon={b.icon} name={b.name} size={15} />
+            </span>
+            <span className="min-w-0 flex-1 flex items-center justify-between gap-2">
+              <span className="j13-bcard-name truncate">{b.name}</span>
+              <span className="meta shrink-0 text-[11px] tabular-nums">{b.post_count} 篇</span>
+            </span>
+          </Link>
+        ))}
+      </div>
+
+      {showAdmin ? (
+        <div className="shrink-0 mt-1.5 pt-1.5" style={{ borderTop: "1px solid var(--line)" }}>
+          <Link href="/admin" className="j13-bcard">
+            <span
+              className="j13-bcard-ico"
+              style={{ background: "var(--accent-soft)", color: "var(--accent)" }}
+              aria-hidden="true"
+            >
+              <ShieldCheck size={15} />
+            </span>
+            <span className="j13-bcard-name flex-1 truncate">管理面板</span>
+          </Link>
+        </div>
+      ) : null}
+    </section>
+  );
+}
+
+// 桌面左栏：整块模块，与右栏 j13-module 对齐
+export function WorkspaceNav({ boards, user }: { boards: BoardWithCount[]; user?: User | null }) {
   return (
     // sticky 必须挂在 flex 子项上：父级 items-start 会把内层缩成内容高，失去粘滞行程
     <nav
       className="hidden lg:block w-56 xl:w-60 shrink-0 sticky top-[var(--rail-top)] max-h-[var(--rail-max-h)]"
       aria-label="工作台导航"
     >
-      <section className="j13-module flex max-h-[var(--rail-max-h)] flex-col overflow-hidden">
-        <p className="j13-module-title shrink-0">
-          <LayoutGrid size={15} style={{ color: "var(--accent)" }} aria-hidden />
-          板块目录
-          {boards.length > 0 ? (
-            <span className="ml-auto meta text-[11.5px] font-medium tracking-normal tabular-nums">
-              {boards.length} 个
-            </span>
-          ) : null}
-        </p>
-
-        <div className="j13-rail-scroll j13-board-list mt-2.5 min-h-0 flex-1">
-          <Link
-            href="/"
-            className="j13-bcard"
-            aria-current={activeBoard === 0 ? "page" : undefined}
-          >
-            <span
-              className="j13-bcard-ico"
-              style={{ background: "var(--accent-soft)", color: "var(--accent)" }}
-              aria-hidden="true"
-            >
-              <Home size={15} />
-            </span>
-            <span className="j13-bcard-name flex-1 truncate">全部讨论</span>
-          </Link>
-
-          {boards.length > 0 ? <div className="j13-board-split" role="separator" /> : null}
-
-          {boards.map((b) => (
-            <Link
-              key={b.id}
-              href={boardHref(b.id)}
-              className="j13-bcard"
-              aria-current={activeBoard === b.id ? "page" : undefined}
-              aria-label={`${b.name}板块，${b.post_count} 篇讨论`}
-            >
-              <span className={`av-${boardColor(b)} j13-bcard-ico`} aria-hidden="true">
-                <BoardIcon icon={b.icon} name={b.name} size={15} />
-              </span>
-              <span className="min-w-0 flex-1 flex items-center justify-between gap-2">
-                <span className="j13-bcard-name truncate">{b.name}</span>
-                <span className="meta shrink-0 text-[11px] tabular-nums">{b.post_count} 篇</span>
-              </span>
-            </Link>
-          ))}
-        </div>
-
-        {showAdmin ? (
-          <div className="shrink-0 mt-1.5 pt-1.5" style={{ borderTop: "1px solid var(--line)" }}>
-            <Link href="/admin" className="j13-bcard">
-              <span
-                className="j13-bcard-ico"
-                style={{ background: "var(--accent-soft)", color: "var(--accent)" }}
-                aria-hidden="true"
-              >
-                <ShieldCheck size={15} />
-              </span>
-              <span className="j13-bcard-name flex-1 truncate">管理面板</span>
-            </Link>
-          </div>
-        ) : null}
-      </section>
+      <WorkspaceNavPanel boards={boards} user={user} />
     </nav>
   );
 }