公开页补齐自引用 Canonical 与按类型的结构化数据，图片补上说明文字。

后台设置和内容编辑改成可导航布局；部署用访客 origin 生成 Canonical，避免落到容器地址。

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/lib/siteUrl.test.ts

@@ -0,0 +1,117 @@
+import assert from "node:assert/strict";
+import { afterEach, describe, it } from "node:test";
+import {
+  absoluteCanonical,
+  canonicalPage,
+  canonicalPath,
+  homeCanonicalQuery,
+  isTrackingParam,
+  parseSiteOrigin,
+  resolveSiteOrigin,
+} from "./siteUrl.ts";
+
+const prev = {
+  SITE_URL: process.env.SITE_URL,
+  NODE_ENV: process.env.NODE_ENV,
+};
+
+afterEach(() => {
+  if (prev.SITE_URL === undefined) delete process.env.SITE_URL;
+  else process.env.SITE_URL = prev.SITE_URL;
+  process.env.NODE_ENV = prev.NODE_ENV;
+});
+
+describe("parseSiteOrigin", () => {
+  it("去掉尾斜杠并保留端口", () => {
+    assert.equal(parseSiteOrigin("https://bbs.example.com/"), "https://bbs.example.com");
+    assert.equal(parseSiteOrigin("http://localhost:3000/"), "http://localhost:3000");
+  });
+  it("拒绝 API / 容器名 / 带路径 / 非 http", () => {
+    assert.equal(parseSiteOrigin("http://api:3001"), null);
+    assert.equal(parseSiteOrigin("https://bbs.example.com/forum"), null);
+    assert.equal(parseSiteOrigin("ftp://bbs.example.com"), null);
+    assert.equal(parseSiteOrigin("not-a-url"), null);
+    assert.equal(parseSiteOrigin(""), null);
+  });
+  it("生产态把容器 API 地址视为非法", () => {
+    process.env.SITE_URL = "http://api:3001";
+    process.env.NODE_ENV = "production";
+    assert.equal(resolveSiteOrigin(), null);
+  });
+});
+
+describe("resolveSiteOrigin", () => {
+  it("开发态无配置回退 localhost:3000", () => {
+    delete process.env.SITE_URL;
+    process.env.NODE_ENV = "development";
+    assert.equal(resolveSiteOrigin(), "http://localhost:3000");
+  });
+  it("生产态缺失不回退 localhost", () => {
+    delete process.env.SITE_URL;
+    process.env.NODE_ENV = "production";
+    assert.equal(resolveSiteOrigin(), null);
+  });
+  it("生产态使用 SITE_URL", () => {
+    process.env.SITE_URL = "https://bbs.example.com/";
+    process.env.NODE_ENV = "production";
+    assert.equal(resolveSiteOrigin(), "https://bbs.example.com");
+  });
+});
+
+describe("canonicalPath", () => {
+  it("首页无尾斜杠参数", () => {
+    assert.equal(canonicalPath("/"), "/");
+    assert.equal(canonicalPath("/post/12/"), "/post/12");
+  });
+  it("省略空值并丢掉追踪参数", () => {
+    assert.equal(
+      canonicalPath("/post/12", { utm_source: "x", fbclid: "1", page: 2, q: "" }),
+      "/post/12?page=2"
+    );
+  });
+  it("保留内容参数", () => {
+    assert.equal(canonicalPath("/", { board: 3, sort: "new", page: 2 }), "/?board=3&page=2&sort=new");
+  });
+});
+
+describe("canonicalPage", () => {
+  it("第一页与非法页码省略", () => {
+    assert.equal(canonicalPage(undefined), undefined);
+    assert.equal(canonicalPage("1"), undefined);
+    assert.equal(canonicalPage("0"), undefined);
+    assert.equal(canonicalPage("foo"), undefined);
+    assert.equal(canonicalPage("2"), 2);
+  });
+});
+
+describe("isTrackingParam", () => {
+  it("识别 utm 与常见点击 id", () => {
+    assert.equal(isTrackingParam("utm_source"), true);
+    assert.equal(isTrackingParam("gclid"), true);
+    assert.equal(isTrackingParam("page"), false);
+  });
+});
+
+describe("absoluteCanonical", () => {
+  it("拼出绝对地址", () => {
+    process.env.SITE_URL = "https://bbs.example.com";
+    process.env.NODE_ENV = "production";
+    assert.equal(absoluteCanonical("/post/9", { page: 2 }), "https://bbs.example.com/post/9?page=2");
+  });
+});
+
+describe("homeCanonicalQuery", () => {
+  it("默认排序与第一页省略；搜索丢掉 board", () => {
+    assert.deepEqual(homeCanonicalQuery({}, true), {});
+    assert.deepEqual(homeCanonicalQuery({ sort: "latest", page: "1" }, true), {});
+    assert.deepEqual(homeCanonicalQuery({ sort: "new" }, false), {});
+    assert.deepEqual(
+      homeCanonicalQuery({ q: " go ", board: "3", page: "2" }, true),
+      { q: "go", page: 2 }
+    );
+    assert.deepEqual(
+      homeCanonicalQuery({ board: "3", sort: "new", page: "2" }, true),
+      { board: 3, page: 2, sort: "new" }
+    );
+  });
+});