feat(structure): compact archive + tag pages + hero/featured, and fix site search

Found a real bug while verifying the nav search: /pagefind/pagefind.js is an ES
module that defines no window.Pagefind, but Search.astro loaded it with a classic
<script src> and read window.Pagefind — so every query answered "Search is
unavailable." (confirmed live before the fix). Now a dynamic import; the specifier
must be a variable or Rollup resolves it at build time and the build fails.

Measured before/after in a real browser:

- archive /posts/ + /zh/posts/: 18,220px -> 3,788px (71 rows at 44px, grouped by
  year) with a client-side filter (title/tags/description text, category chips,
  14 tag chips, zero requests). Tested: "nginx" -> 6 rows, chip devops -> 28.
- tag pages for tags with >= 3 posts. Measured 235 distinct tags (an earlier brief
  claimed 74), 156 used exactly once — pages only where a topic exists: 40 tags ->
  80 pages, build 165 -> 245 pages. Pills link only when a page exists.
- homepage + ZH homepage: hero (288px) with the real scale claim, three CTAs, a
  fixed Featured 4 (scale -> automation -> observability -> a delivered result),
  Latest 10 -> 6. ZH hero had linked "关于我" to the English /about/.
- long code blocks collapse above 420px with an Expand button + gradient, copy
  button still copies the whole block (verified on the 1010px block).
- search is visible ("⌕ Search /" pill, "/" plus the existing Ctrl/Cmd+K) and the
  zero-result screen offers topic chips instead of a dead end.

Docs: project-state B3 entry, ops-runbook Pagefind gotcha.

src/components/Archive.astro

@@ -0,0 +1,238 @@
+---
+import type { CollectionEntry } from 'astro:content';
+import { tagCounts, tagHref } from '../lib/tags';
+
+interface Props {
+  posts: CollectionEntry<'posts'>[];
+  lang?: 'en' | 'zh';
+  /** Filter bar + chips. Off on tag/collection pages, where the set is already narrow. */
+  chrome?: boolean;
+}
+const { posts, lang = 'en', chrome = true } = Astro.props;
+const isZh = lang === 'zh';
+
+const counts = tagCounts(posts);
+const years = [...new Set(posts.map((p) => p.data.pubDate.getUTCFullYear()))].sort((a, b) => b - a);
+const categories = [...new Set(posts.map((p) => p.data.category))]
+  .map((c) => ({ name: c, n: posts.filter((p) => p.data.category === c).length }))
+  .sort((a, b) => b.n - a.n);
+// Only tags that have their own page become chips — a chip that leads nowhere is the
+// same trap the old non-clickable pills were.
+const chips = [...counts.entries()]
+  .filter(([, n]) => n >= 3)
+  .sort((a, b) => b[1] - a[1])
+  .slice(0, 14)
+  .map(([t, n]) => ({ tag: t, n }));
+
+const shortDate = (d: Date) =>
+  `${String(d.getUTCMonth() + 1).padStart(2, '0')}-${String(d.getUTCDate()).padStart(2, '0')}`;
+const yearOf = (d: Date) => d.getUTCFullYear();
+
+const labels = isZh
+  ? { filter: '按标题或标签筛选…', all: '全部', empty: '没有匹配的文章。', search: '全文搜索', count: '篇' }
+  : { filter: 'Filter by title or tag…', all: 'All', empty: 'No posts match.', search: 'Full-text search', count: 'posts' };
+---
+
+{chrome && (
+  <>
+<div class="archive-bar">
+  <input
+    type="search"
+    id="archive-q"
+    class="archive-input"
+    placeholder={labels.filter}
+    autocomplete="off"
+    aria-label={labels.filter}
+  />
+  <button class="archive-overlay-btn" id="archive-search" type="button">⌕ {labels.search}</button>
+</div>
+
+<div class="archive-chips" role="group" aria-label={isZh ? '按分类筛选' : 'Filter by category'}>
+  <button class="chip is-active" data-cat="" type="button">{labels.all} <span>{posts.length}</span></button>
+  {categories.map((c) => (
+    <button class="chip" data-cat={c.name} type="button">{c.name} <span>{c.n}</span></button>
+  ))}
+</div>
+
+<div class="archive-chips archive-tags" role="group" aria-label={isZh ? '按标签筛选' : 'Filter by tag'}>
+  {chips.map((c) => (
+    <a class="chip tag-chip" href={tagHref(c.tag, lang)}>{c.tag} <span>{c.n}</span></a>
+  ))}
+</div>
+  </>
+)}
+{!chrome && <p class="archive-meta">{posts.length} {labels.count}</p>}
+
+<ol class="archive" id="archive-list">
+  {years.map((y) => (
+    <li class="archive-year-block" data-year={y}>
+      <h2 class="archive-year">{y}</h2>
+      <ol class="archive-rows">
+        {posts.filter((p) => yearOf(p.data.pubDate) === y).map((p) => (
+          <li
+            class="archive-row"
+            data-cat={p.data.category}
+            data-tags={p.data.tags.join(' ')}
+            data-q={`${p.data.title} ${p.data.tags.join(' ')} ${p.data.description}`.toLowerCase()}
+          >
+            <time datetime={p.data.pubDate.toISOString()}>{shortDate(p.data.pubDate)}</time>
+            <a class="archive-title" href={`/posts/${p.slug}/`}>{p.data.title}</a>
+            <a class="archive-cat" href={`${isZh ? '/zh' : ''}/categories/${p.data.category}/`}>{p.data.category}</a>
+          </li>
+        ))}
+      </ol>
+    </li>
+  ))}
+</ol>
+
+<p class="archive-empty" id="archive-empty" hidden>{labels.empty}</p>
+
+<style>
+  .archive-bar {
+    display: flex;
+    gap: 0.6rem;
+    align-items: center;
+    margin: 1.25rem 0 0.9rem;
+    flex-wrap: wrap;
+  }
+  .archive-input {
+    flex: 1 1 16rem;
+    min-width: 12rem;
+    background: var(--surface);
+    border: 1px solid var(--border);
+    border-radius: var(--radius);
+    color: var(--ink);
+    font: inherit;
+    font-size: 0.95rem;
+    padding: 0.6rem 0.8rem;
+  }
+  .archive-input:focus { outline: none; border-color: var(--brand); }
+  .archive-overlay-btn {
+    font: inherit;
+    font-size: 0.9rem;
+    color: var(--muted);
+    background: none;
+    border: 1px solid var(--border);
+    border-radius: var(--radius);
+    padding: 0.6rem 0.8rem;
+    cursor: pointer;
+    white-space: nowrap;
+  }
+  .archive-overlay-btn:hover { color: var(--brand); border-color: var(--brand); }
+
+  .archive-chips { display: flex; flex-wrap: wrap; gap: 0.4rem; margin-bottom: 0.5rem; }
+  .archive-tags { margin-bottom: 1.1rem; }
+  .chip {
+    font: inherit;
+    font-size: 0.78rem;
+    color: var(--muted);
+    background: var(--surface);
+    border: 1px solid var(--border);
+    border-radius: 999px;
+    padding: 0.22rem 0.6rem;
+    cursor: pointer;
+    text-decoration: none;
+    white-space: nowrap;
+  }
+  .chip span { opacity: 0.55; margin-left: 0.15rem; }
+  .chip:hover { color: var(--brand); border-color: var(--brand); }
+  .chip.is-active { color: var(--ink); border-color: var(--brand); }
+
+  .archive { list-style: none; padding: 0; margin: 0; }
+  .archive-year {
+    font-size: 0.8rem;
+    letter-spacing: 0.08em;
+    text-transform: uppercase;
+    color: var(--faint);
+    margin: 1.4rem 0 0.4rem;
+    padding-bottom: 0.3rem;
+    border-bottom: 1px solid var(--border);
+  }
+  .archive-rows { list-style: none; padding: 0; margin: 0; }
+  .archive-row {
+    display: flex;
+    align-items: center;
+    gap: 0.8rem;
+    min-height: 44px;
+    border-bottom: 1px solid color-mix(in srgb, var(--border) 45%, transparent);
+  }
+  .archive-row time {
+    flex: 0 0 3.2rem;
+    font-family: var(--font-mono);
+    font-size: 0.8rem;
+    color: var(--faint);
+  }
+  .archive-title {
+    flex: 1 1 auto;
+    color: var(--ink);
+    text-decoration: none;
+    font-size: 0.95rem;
+    line-height: 1.35;
+  }
+  .archive-title:hover { color: var(--brand); }
+  .archive-cat {
+    flex: 0 0 auto;
+    font-size: 0.72rem;
+    color: var(--muted);
+    text-decoration: none;
+    border: 1px solid var(--border);
+    border-radius: 999px;
+    padding: 0.1em 0.55em;
+  }
+  .archive-cat:hover { color: var(--brand); border-color: var(--brand); }
+  .archive-empty { color: var(--muted); margin-top: 1.5rem; }
+  [hidden] { display: none !important; }
+
+  @media (max-width: 600px) {
+    .archive-row { flex-wrap: wrap; gap: 0.3rem 0.6rem; padding: 0.4rem 0; }
+    .archive-title { flex: 1 1 100%; order: 2; }
+    .archive-row time { flex: 0 0 auto; order: 1; }
+    .archive-cat { order: 1; }
+  }
+</style>
+
+<script>
+  // Client-side filter over an already-rendered list: zero network requests, works
+  // with the browser's own Ctrl+F, and keeps the archive one static page.
+  const q = document.getElementById('archive-q') as HTMLInputElement | null;
+  const list = document.getElementById('archive-list');
+  const empty = document.getElementById('archive-empty');
+  const chips = Array.from(document.querySelectorAll('.chip[data-cat]'));
+  const overlayBtn = document.getElementById('archive-search');
+  let activeCat = '';
+
+  overlayBtn?.addEventListener('click', () => {
+    document.getElementById('search-toggle')?.click();
+  });
+
+  function apply() {
+    const term = (q?.value ?? '').trim().toLowerCase();
+    const terms = term ? term.split(/\s+/) : [];
+    let shown = 0;
+    document.querySelectorAll('.archive-row').forEach((row) => {
+      const el = row as HTMLElement;
+      const cat = el.dataset.cat ?? '';
+      const hay = el.dataset.q ?? '';
+      const okCat = !activeCat || cat === activeCat;
+      const okTerm = terms.every((t) => hay.includes(t));
+      const ok = okCat && okTerm;
+      el.hidden = !ok;
+      if (ok) shown++;
+    });
+    document.querySelectorAll('.archive-year-block').forEach((block) => {
+      const el = block as HTMLElement;
+      const any = Array.from(el.querySelectorAll('.archive-row')).some((r) => !(r as HTMLElement).hidden);
+      el.hidden = !any;
+    });
+    if (empty) empty.hidden = shown !== 0;
+  }
+
+  q?.addEventListener('input', apply);
+  chips.forEach((chip) => {
+    chip.addEventListener('click', () => {
+      activeCat = (chip as HTMLElement).dataset.cat ?? '';
+      chips.forEach((c) => c.classList.toggle('is-active', c === chip));
+      apply();
+    });
+  });
+</script>

src/components/PostList.astro

@@ -1,5 +1,8 @@
 ---
 import type { CollectionEntry } from 'astro:content';
+import { getCollection } from 'astro:content';
+import { postLang } from '../lib/lang';
+import { tagCounts, tagLink } from '../lib/tags';
 
 interface Props {
   posts: CollectionEntry<'posts'>[];
@@ -24,6 +27,10 @@ const catHref = (cat: string) => `/${isZh ? 'zh/categories' : 'categories'}/${ca
 
 const og = (post: CollectionEntry<'posts'>) => post.data.ogImage || '/og-default.png';
 
+// Tag pills only link when the tag has its own page (>= TAG_MIN_POSTS in this language).
+const counts = tagCounts((await getCollection('posts', ({ data }) => !data.draft))
+  .filter((p) => postLang(p.slug) === lang));
+
 // The row thumbnail is displayed at ~398 CSS px wide, so the list used to pull a
 // 1200x630 PNG (~45 KB) per row for a 398px slot. Serve 400w/800w WebP derived from
 // the same art instead (5.8 KB / 16.1 KB — see scripts/optimize-images.py).
@@ -64,7 +71,10 @@ const thumb = (post: CollectionEntry<'posts'>, w: 400 | 800) =>
           )}
           <span class="sep">·</span>
           <a class="tag" href={catHref(post.data.category)}>{post.data.category}</a>
-          {post.data.tags.map((t) => <span class="tag">{t}</span>)}
+          {post.data.tags.map((t) => {
+            const href = tagLink(t, counts, lang);
+            return href ? <a class="tag" href={href}>{t}</a> : <span class="tag">{t}</span>;
+          })}
         </div>
         <p>{post.data.description}</p>
       </div>

src/components/Search.astro

@@ -11,6 +11,13 @@ const placeholder =
   lang === 'zh' ? '搜索文章…' : 'Search posts…';
 const noResults =
   lang === 'zh' ? '没有匹配的结果。' : 'No results.';
+// Empty-search state: a dead end helps nobody. Offer the topic entry points that
+// actually exist (tag pages are generated for tags with >= 3 posts).
+const popular = ['docker', 'self-hosting', 'nginx', 'monitoring', 'automation'];
+const popularHref = (t: string) => (lang === 'zh' ? `/zh/tags/${t}/` : `/tags/${t}/`);
+const tryLabel = lang === 'zh' ? '试试这些主题：' : 'Try a topic:';
+const archiveLabel = lang === 'zh' ? '浏览全部文章' : 'Browse all posts';
+const archiveHref = lang === 'zh' ? '/zh/posts/' : '/posts/';
 ---
 
 <div class="search-overlay" id="search-overlay" hidden>
@@ -28,6 +35,16 @@ const noResults =
     </div>
     <div class="search-results" id="search-results"></div>
   </div>
+
+  <!-- Dead-end screen for a search with no hits: real links, rendered at build time. -->
+  <template id="search-empty-tpl">
+    <p class="excerpt" data-role="message">{noResults}</p>
+    <p class="excerpt" data-role="try">{tryLabel}</p>
+    <p class="search-empty-chips">
+      {popular.map((t) => <a class="chip" href={popularHref(t)}>{t}</a>)}
+      <a class="chip" href={archiveHref}>{archiveLabel}</a>
+    </p>
+  </template>
 </div>
 
 <style>
@@ -88,6 +105,17 @@ const noResults =
   .search-result:hover { color: var(--brand); }
   .search-result h3 { margin: 0 0 0.2rem; font-size: 1.05rem; }
   .search-result .excerpt { color: var(--muted); font-size: 0.88rem; margin: 0; }
+  .search-empty-chips { display: flex; flex-wrap: wrap; gap: 0.4rem; margin-top: 0.5rem; }
+  .search-empty .chip {
+    color: var(--muted);
+    background: var(--surface);
+    border: 1px solid var(--border);
+    border-radius: 999px;
+    padding: 0.22rem 0.6rem;
+    font-size: 0.78rem;
+    text-decoration: none;
+  }
+  .search-empty .chip:hover { color: var(--brand); border-color: var(--brand); }
   .search-result mark {
     background: color-mix(in srgb, var(--brand) 25%, transparent);
     color: var(--ink);
@@ -140,17 +168,17 @@ const noResults =
 
   async function loadPagefind() {
     if (pagefind) return pagefind;
-    // Pagefind's UI/JS is copied into /pagefind/ post-build. Load it via a
-    // script tag (not a dynamic import) so Vite leaves the URL untouched.
-    await new Promise<void>((resolve, reject) => {
-      const s = document.createElement('script');
-      s.src = '/pagefind/pagefind.js';
-      s.onload = () => resolve();
-      s.onerror = () => reject(new Error('pagefind load failed'));
-      document.head.appendChild(s);
-    });
-    const w = window as unknown as { Pagefind?: Pagefind };
-    pagefind = w.Pagefind;
+    // /pagefind/pagefind.js is copied into the build post-build. It is an **ES module**
+    // (`export { search, debouncedSearch, … }`) and defines NO window global, so loading
+    // it with a classic <script src> leaves window.Pagefind undefined and every search
+    // answered "Search is unavailable." — which is what happened between the search
+    // shipping and this fix. Import it as a module instead; @vite-ignore keeps Vite from
+    // trying to resolve a path that only exists in dist/.
+    // The specifier must be a VARIABLE: Rollup resolves a literal dynamic-import path
+    // at build time (and @vite-ignore does not stop it), which breaks the build because
+    // /pagefind/ only exists in dist/ after the index is generated.
+    const url = '/pagefind/pagefind.js';
+    pagefind = (await import(/* @vite-ignore */ url)) as unknown as Pagefind;
     return pagefind;
   }
 
@@ -169,10 +197,11 @@ const noResults =
         const res = await search;
         results.innerHTML = '';
         if (!res.results.length) {
-          const empty = document.createElement('p');
-          empty.className = 'excerpt';
-          empty.textContent = 'No results.';
-          results.appendChild(empty);
+          // Clone the build-time template: the links cannot drift from the pages that
+          // actually exist (tag pages are only generated for tags with >= 3 posts).
+          results.innerHTML = '';
+          const tpl = document.getElementById('search-empty-tpl') as HTMLTemplateElement | null;
+          if (tpl) results.appendChild(tpl.content.cloneNode(true));
           return;
         }
         for (const r of res.results.slice(0, 12)) {