feat: v2.3.0 - 新闻获取准确性优化

核心改进：
1. 新增专用新闻关键词字段（sites.news_keywords）
2. 严格匹配搜索策略（双引号包裹关键词）
3. 前台手动刷新新闻功能

数据库变更：
- Sites表添加news_keywords字段（VARCHAR(200)）
- 提供迁移脚本migrate_news_keywords.py

代码变更：
- models.py: Site模型添加news_keywords字段
- app.py: 后台表单配置、API路由、search_site_news调用优化
- utils/news_searcher.py: 支持news_keywords参数优先匹配
- templates/detail_new.html: 添加刷新按钮和JavaScript

新增功能：
- 后台可为每个网站设置专属新闻关键词
- 详情页"获取最新资讯"按钮（前台可用，无需登录）
- 新API端点：POST /api/refresh-site-news/<site_code>

文档：
- DEPLOY_v2.3.0.md: 完整部署指南
- DEPLOY_v2.3_QUICK.md: 快速部署指南

向后兼容：
- 现有网站自动使用网站名称作为默认关键词
- 未设置关键词时降级使用网站名称搜索

🤖 Generated with Claude Code (https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

templates/detail_new.html

@@ -622,10 +622,16 @@
             <!-- Related News -->
             {% if news_list %}
             <div class="content-block">
-                <h2>
-                    <span>📰</span>
-                    相关新闻
-                </h2>
+                <div style="display: flex; justify-content: space-between; align-items: center; margin-bottom: 20px;">
+                    <h2 style="margin: 0;">
+                        <span>📰</span>
+                        相关新闻
+                    </h2>
+                    <button id="refreshNewsBtn" class="refresh-news-btn" onclick="refreshNews('{{ site.code }}')">
+                        <span class="refresh-icon">↻</span> 获取最新资讯
+                    </button>
+                </div>
+                <div id="newsContainer">
                 {% for news in news_list %}
                 <div class="news-item">
                     <div style="display: flex; justify-content: space-between; align-items: flex-start; margin-bottom: 12px;">
@@ -667,6 +673,7 @@
                     </div>
                 </div>
                 {% endfor %}
+                </div><!-- End newsContainer -->
             </div>
             {% endif %}
         </div>
@@ -698,4 +705,127 @@
         </div>
     </div>
 </div>
+
+<style>
+.refresh-news-btn {
+    padding: 8px 16px;
+    background: linear-gradient(135deg, var(--primary-blue) 0%, var(--primary-dark) 100%);
+    color: white;
+    border: none;
+    border-radius: 8px;
+    font-size: 13px;
+    font-weight: 500;
+    cursor: pointer;
+    transition: all 0.3s;
+    display: flex;
+    align-items: center;
+    gap: 6px;
+}
+
+.refresh-news-btn:hover {
+    transform: translateY(-2px);
+    box-shadow: 0 4px 12px rgba(14, 165, 233, 0.3);
+}
+
+.refresh-news-btn:disabled {
+    opacity: 0.6;
+    cursor: not-allowed;
+    transform: none;
+}
+
+.refresh-news-btn.loading .refresh-icon {
+    animation: spin 1s linear infinite;
+}
+
+@keyframes spin {
+    from { transform: rotate(0deg); }
+    to { transform: rotate(360deg); }
+}
+
+.news-status {
+    padding: 12px;
+    margin: 16px 0;
+    border-radius: 8px;
+    font-size: 14px;
+    display: none;
+}
+
+.news-status.success {
+    background: rgba(34, 197, 94, 0.1);
+    border: 1px solid rgba(34, 197, 94, 0.3);
+    color: #22c55e;
+}
+
+.news-status.error {
+    background: rgba(239, 68, 68, 0.1);
+    border: 1px solid rgba(239, 68, 68, 0.3);
+    color: #ef4444;
+}
+</style>
+
+<script>
+function refreshNews(siteCode) {
+    const btn = document.getElementById('refreshNewsBtn');
+    const newsContainer = document.getElementById('newsContainer');
+
+    if (!btn || !newsContainer) return;
+
+    // 禁用按钮，显示加载状态
+    btn.disabled = true;
+    btn.classList.add('loading');
+    btn.innerHTML = '<span class="refresh-icon">↻</span> 正在获取...';
+
+    // 显示加载提示
+    const loadingMsg = document.createElement('div');
+    loadingMsg.className = 'news-status';
+    loadingMsg.style.display = 'block';
+    loadingMsg.textContent = '正在获取最新资讯，请稍候...';
+    newsContainer.insertAdjacentElement('beforebegin', loadingMsg);
+
+    // 调用刷新API
+    fetch(`/api/refresh-site-news/${siteCode}`, {
+        method: 'POST',
+        headers: {
+            'Content-Type': 'application/json'
+        }
+    })
+    .then(response => response.json())
+    .then(data => {
+        if (data.success) {
+            // 刷新成功，重新加载页面
+            loadingMsg.className = 'news-status success';
+            loadingMsg.textContent = `✓ 成功获取 ${data.saved_count || 0} 条新资讯，页面即将刷新...`;
+            setTimeout(() => {
+                window.location.reload();
+            }, 1500);
+        } else {
+            // 刷新失败
+            loadingMsg.className = 'news-status error';
+            loadingMsg.textContent = `✗ ${data.message || '获取失败，请稍后重试'}`;
+            btn.disabled = false;
+            btn.classList.remove('loading');
+            btn.innerHTML = '<span class="refresh-icon">↻</span> 获取最新资讯';
+
+            // 3秒后隐藏错误消息
+            setTimeout(() => {
+                loadingMsg.style.display = 'none';
+            }, 3000);
+        }
+    })
+    .catch(error => {
+        console.error('Error:', error);
+        loadingMsg.className = 'news-status error';
+        loadingMsg.textContent = '✗ 网络请求失败，请检查网络连接';
+        btn.disabled = false;
+        btn.classList.remove('loading');
+        btn.innerHTML = '<span class="refresh-icon">↻</span> 获取最新资讯';
+
+        // 3秒后隐藏错误消息
+        setTimeout(() => {
+            loadingMsg.style.display = 'none';
+        }, 3000);
+    });
+}
+</script>
+
 {% endblock %}