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/lib/widgetCode.test.ts

@@ -0,0 +1,102 @@
+import assert from "node:assert/strict";
+import { describe, it } from "node:test";
+import { mergeWidgetCode, parseMixedWidgetCode, scopeWidgetCss } from "./widgetCode.ts";
+
+describe("parseMixedWidgetCode", () => {
+  it("拆分混写的 style/script 段", () => {
+    const r = parseMixedWidgetCode(
+      `<div class="a">hi</div>\n<style>.a { color: red; }</style>\n<script>console.log(1);</script>`
+    );
+    assert.equal(r.html, `<div class="a">hi</div>`);
+    assert.equal(r.css, `.a { color: red; }`);
+    assert.equal(r.js, `console.log(1);`);
+  });
+
+  it("多段 style/script 按序拼接", () => {
+    const r = parseMixedWidgetCode(`<style>.a{}</style><style>.b{}</style><p>x</p><script>a();</script><script>b();</script>`);
+    assert.equal(r.css, ".a{}\n\n.b{}");
+    assert.equal(r.js, "a();\n\nb();");
+    assert.equal(r.html, "<p>x</p>");
+  });
+
+  it("纯 HTML 不误伤", () => {
+    const r = parseMixedWidgetCode(`<p>hello</p>`);
+    assert.deepEqual(r, { html: "<p>hello</p>", css: "", js: "" });
+  });
+
+  it("外链与非 JS type 的 script 留在 html", () => {
+    const code = `<script src="https://x/y.js"></script><script type="application/json">{"a":1}</script><script>z();</script>`;
+    const r = parseMixedWidgetCode(code);
+    assert.equal(r.js, "z();");
+    assert.equal(
+      r.html,
+      `<script src="https://x/y.js"></script><script type="application/json">{"a":1}</script>`
+    );
+  });
+});
+
+describe("mergeWidgetCode", () => {
+  it("合并后再解析可还原三字段", () => {
+    const parts = { html: "<b>go</b>", css: "b { font-size: 18px; }", js: "x();" };
+    assert.deepEqual(parseMixedWidgetCode(mergeWidgetCode(parts)), parts);
+  });
+
+  it("空段不产生标签", () => {
+    assert.equal(mergeWidgetCode({ html: "hi", css: "", js: "" }), "hi");
+  });
+});
+
+describe("scopeWidgetCss", () => {
+  const p = ".j13-widget-7";
+
+  it("普通规则加前缀", () => {
+    assert.equal(scopeWidgetCss(".a { color: red; }", 7), `${p} .a { color: red; }`);
+  });
+
+  it("选择器列表逐个前缀，括号内逗号不分割", () => {
+    assert.equal(
+      scopeWidgetCss(".a, .b {}", 7),
+      `${p} .a, ${p} .b {}`
+    );
+    assert.equal(
+      scopeWidgetCss(':is(.a, .b) { color: red }', 7),
+      `${p} :is(.a, .b) { color: red }`
+    );
+  });
+
+  it("root/body 选择器替换为容器本身", () => {
+    assert.equal(scopeWidgetCss(":root { --x: 1; }", 7), `${p} { --x: 1; }`);
+    assert.equal(scopeWidgetCss("body { margin: 0 }", 7), `${p} { margin: 0 }`);
+    assert.equal(scopeWidgetCss("body .card {}", 7), `${p} .card {}`);
+  });
+
+  it("容器自身伪类紧贴前缀", () => {
+    assert.equal(scopeWidgetCss(":hover { opacity: .8 }", 7), `${p}:hover { opacity: .8 }`);
+  });
+
+  it("@media 内层前缀化，头部原样", () => {
+    assert.equal(
+      scopeWidgetCss("@media (min-width: 10px) { .a {} }", 7),
+      `@media (min-width: 10px) { ${p} .a {} }`
+    );
+  });
+
+  it("@keyframes 原样保留", () => {
+    const css = "@keyframes spin { from { opacity: 0 } to { opacity: 1 } }";
+    assert.equal(scopeWidgetCss(css, 7), css);
+  });
+
+  it("@import 语句原样保留", () => {
+    assert.equal(
+      scopeWidgetCss('@import url("a.css"); .a {}', 7),
+      '@import url("a.css"); .j13-widget-7 .a {}'
+    );
+  });
+
+  it("注释与字符串内的花括号不干扰配对", () => {
+    assert.equal(
+      scopeWidgetCss("/* { nope } */ .a::after { content: \"{\" }", 7),
+      `/* { nope } */ ${p} .a::after { content: "{" }`
+    );
+  });
+});