feat: add daily tip & case auto-publish system

- GitHub Actions workflow: daily-content.yml (UTC 00:00 / 北京 08:00)
- Content generation script: .github/scripts/generate-daily.js (Claude API)
- Initial data: website/daily/data.json
- website/index.html: new 每日精选 section with bilingual support

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

website/index.html

@@ -309,6 +309,61 @@
 
         .hidden { display: none !important; }
 
+        /* Daily section */
+        .daily-grid {
+            display: grid;
+            grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
+            gap: 24px;
+            margin-bottom: 32px;
+        }
+        .daily-card {
+            background: var(--surface);
+            border: 1px solid var(--border);
+            border-radius: 16px;
+            padding: 28px;
+            transition: border-color 0.2s;
+        }
+        .daily-card:hover { border-color: var(--accent); }
+        .daily-card-header {
+            display: flex;
+            align-items: center;
+            gap: 10px;
+            margin-bottom: 14px;
+        }
+        .daily-date {
+            text-align: center;
+            color: var(--text-dim);
+            font-size: 14px;
+            margin-bottom: 32px;
+        }
+        .daily-history {
+            margin-top: 32px;
+        }
+        .daily-history-toggle {
+            display: block;
+            width: 100%;
+            background: transparent;
+            border: 1px solid var(--border);
+            color: var(--text-dim);
+            padding: 10px;
+            border-radius: 10px;
+            cursor: pointer;
+            font-size: 14px;
+            transition: all 0.2s;
+        }
+        .daily-history-toggle:hover { border-color: var(--accent); color: var(--text); }
+        .daily-history-list { display: none; margin-top: 20px; }
+        .daily-history-list.open { display: block; }
+        .daily-history-item {
+            border-top: 1px solid var(--border);
+            padding: 20px 0;
+        }
+        .daily-history-item-date {
+            font-size: 13px;
+            color: var(--text-dim);
+            margin-bottom: 12px;
+        }
+
         @media (max-width: 640px) {
             .stats { gap: 24px; }
             .hero-cta { flex-direction: column; align-items: center; }
@@ -642,6 +697,63 @@
     </div>
 </section>
 
+<!-- Daily Tip & Case -->
+<section id="daily" style="border-top: 1px solid var(--border); padding-top: 80px;">
+    <h2>
+        <span class="zh">每日精选</span>
+        <span class="en hidden">Daily Picks</span>
+    </h2>
+    <p class="section-sub">
+        <span class="zh">每天更新 · OpenClaw / U-Claw 使用技巧与最佳案例</span>
+        <span class="en hidden">Updated daily · Tips &amp; best-practice cases for OpenClaw / U-Claw</span>
+    </p>
+
+    <div id="daily-date" class="daily-date"></div>
+
+    <div id="daily-loading" style="text-align:center;color:var(--text-dim);padding:40px 0;">
+        <span class="zh">加载中…</span><span class="en hidden">Loading…</span>
+    </div>
+
+    <div id="daily-content" style="display:none;">
+        <div class="daily-grid">
+            <!-- Tip card -->
+            <div class="daily-card">
+                <div class="daily-card-header">
+                    <span class="tag tag-blue" style="margin-bottom:0;">
+                        <span class="zh">技巧</span><span class="en hidden">Tip</span>
+                    </span>
+                </div>
+                <h3 id="tip-title" style="font-size:18px;margin-bottom:10px;"></h3>
+                <p id="tip-content" style="color:var(--text-dim);font-size:14px;line-height:1.8;"></p>
+            </div>
+            <!-- Case card -->
+            <div class="daily-card">
+                <div class="daily-card-header">
+                    <span class="tag tag-green" style="margin-bottom:0;">
+                        <span class="zh">案例</span><span class="en hidden">Case</span>
+                    </span>
+                </div>
+                <h3 id="case-title" style="font-size:18px;margin-bottom:10px;"></h3>
+                <p id="case-content" style="color:var(--text-dim);font-size:14px;line-height:1.8;"></p>
+            </div>
+        </div>
+
+        <!-- History -->
+        <div class="daily-history">
+            <button class="daily-history-toggle" onclick="toggleDailyHistory(this)">
+                <span class="zh">查看最近 7 天历史 ▼</span>
+                <span class="en hidden">Recent 7 days history ▼</span>
+            </button>
+            <div class="daily-history-list" id="daily-history-list"></div>
+        </div>
+    </div>
+
+    <div id="daily-error" style="display:none;text-align:center;color:var(--text-dim);padding:40px 0;">
+        <span class="zh">内容暂时无法加载，请稍后刷新</span>
+        <span class="en hidden">Content unavailable, please refresh later</span>
+    </div>
+</section>
+
 <!-- CTA -->
 <div class="cta-section">
     <h2>
@@ -774,7 +886,81 @@ function switchLang(lang) {
     document.getElementById('btn-zh').classList.toggle('active', lang === 'zh');
     document.getElementById('btn-en').classList.toggle('active', lang === 'en');
     document.documentElement.lang = lang === 'zh' ? 'zh-CN' : 'en';
+    // Re-render daily content text after lang switch
+    if (window._dailyData) renderDaily(window._dailyData);
 }
+
+function getCurrentLang() {
+    return document.getElementById('btn-zh').classList.contains('active') ? 'zh' : 'en';
+}
+
+function t(obj) {
+    const lang = getCurrentLang();
+    return obj ? (obj[lang] || obj.zh || '') : '';
+}
+
+function renderDaily(data) {
+    const lang = getCurrentLang();
+    const latest = data.latest;
+    if (!latest) return;
+
+    document.getElementById('daily-date').textContent =
+        lang === 'zh' ? `更新日期：${latest.date}` : `Updated: ${latest.date}`;
+
+    document.getElementById('tip-title').textContent = t(latest.tip.title);
+    document.getElementById('tip-content').textContent = t(latest.tip.content);
+    document.getElementById('case-title').textContent = t(latest.case.title);
+    document.getElementById('case-content').textContent = t(latest.case.content);
+
+    // History (up to 7 entries)
+    const histList = document.getElementById('daily-history-list');
+    const recent = (data.history || []).slice(0, 7);
+    histList.innerHTML = recent.map(entry => `
+        <div class="daily-history-item">
+            <div class="daily-history-item-date">${entry.date}</div>
+            <div class="daily-grid" style="margin-bottom:0;">
+                <div class="daily-card">
+                    <div class="daily-card-header">
+                        <span class="tag tag-blue" style="margin-bottom:0;">${t(entry.tip.tag)}</span>
+                    </div>
+                    <h3 style="font-size:16px;margin-bottom:8px;">${t(entry.tip.title)}</h3>
+                    <p style="color:var(--text-dim);font-size:13px;line-height:1.8;">${t(entry.tip.content)}</p>
+                </div>
+                <div class="daily-card">
+                    <div class="daily-card-header">
+                        <span class="tag tag-green" style="margin-bottom:0;">${t(entry.case.tag)}</span>
+                    </div>
+                    <h3 style="font-size:16px;margin-bottom:8px;">${t(entry.case.title)}</h3>
+                    <p style="color:var(--text-dim);font-size:13px;line-height:1.8;">${t(entry.case.content)}</p>
+                </div>
+            </div>
+        </div>`).join('');
+}
+
+function toggleDailyHistory(btn) {
+    const list = document.getElementById('daily-history-list');
+    const open = list.classList.toggle('open');
+    const lang = getCurrentLang();
+    if (lang === 'zh') {
+        btn.querySelector('.zh').textContent = open ? '收起历史 ▲' : '查看最近 7 天历史 ▼';
+    } else {
+        btn.querySelector('.en').textContent = open ? 'Collapse history ▲' : 'Recent 7 days history ▼';
+    }
+}
+
+// Load daily data
+fetch('daily/data.json?v=' + Date.now())
+    .then(r => r.json())
+    .then(data => {
+        window._dailyData = data;
+        document.getElementById('daily-loading').style.display = 'none';
+        document.getElementById('daily-content').style.display = 'block';
+        renderDaily(data);
+    })
+    .catch(() => {
+        document.getElementById('daily-loading').style.display = 'none';
+        document.getElementById('daily-error').style.display = 'block';
+    });
 </script>
 </body>
 </html>