fix(frontend): align search and header components with reference

tests/widget-system/search-reference-contract.test.cjs

@@ -0,0 +1,45 @@
+const test = require('node:test');
+const assert = require('node:assert/strict');
+const fs = require('node:fs');
+const path = require('node:path');
+const { spawnSync } = require('node:child_process');
+
+const root = path.resolve(__dirname, '..', '..');
+const read = (file) => fs.readFileSync(path.join(root, file), 'utf8');
+
+test('search route keeps the reference Zibll results and empty-state structure', () => {
+  const template = read('search.php');
+  const styles = read('assets/css/main.css');
+
+  for (const token of ['search-input', 'search-page-ajaxpager', 'search-tab-header', 'search-filter-item', 'post_ajax_loader']) {
+    assert.match(template + styles, new RegExp(token.replace(/[.*+?^${}()|[\\]\\]/g, '\\$&')));
+  }
+  assert.match(template, /aksrt_get_ajax_null\(__\('请输入搜索关键词'/);
+  assert.match(template, /'null-search\.svg'/);
+  assert.match(template, /user_query instanceof WP_User_Query/);
+  assert.equal(fs.existsSync(path.join(root, 'assets/css/routes/search.css')), false);
+  assert.match(template, /'skip_wrapper' => true/);
+  assert.match(template, /null-user\.svg/);
+  assert.match(template, /null-post\.svg/);
+  assert.match(template, /route-title=/);
+  for (const image of ['null-search.svg', 'null-user.svg', 'null-post.svg']) {
+    assert.match(read(`assets/img/${image}`), /<svg\b/);
+  }
+  assert.equal(fs.existsSync(path.join(root, 'assets/img/null-search.svg')), true);
+  assert.equal(fs.existsSync(path.join(root, 'assets/img/null-user.svg')), true);
+});
+
+test('search rendering preserves form state, result markup, paging and escaped keywords', () => {
+  const result = spawnSync(process.env.PHP_BINARY || 'php', [path.join(__dirname, 'search-render-harness.php')], {
+    cwd: root,
+    encoding: 'utf8',
+  });
+  assert.equal(result.status, 0, result.stderr || result.stdout);
+  assert.match(result.stdout, /Search render harness passed/);
+});
+
+test('search route renders reference fluid widget sidebars in order', () => {
+  const template = read('search.php');
+  assert.match(template, /dynamic_sidebar\('all_top_fluid'\)[\s\S]*dynamic_sidebar\('search_top_fluid'\)/);
+  assert.match(template, /dynamic_sidebar\('search_bottom_fluid'\)[\s\S]*dynamic_sidebar\('all_bottom_fluid'\)/);
+});