feat: 门户网站初始提交

- Go + Gin + html/template 服务端渲染
- 主页：Google 风格搜索框 + 导航卡片
- 后台：卡片 CRUD、搜索引擎配置、主页背景/标题配置
- 图片上传：支持 jpg/jpeg/png/gif，自动压缩，缩略图参数 ?thumb=1
- 安全：登录日志、修改密码、IP 自动封禁、IP 白名单
- 访问统计：主页访问/卡片点击/搜索追踪、实时流量、IP 统计
- SQLite 存储（modernc.org/sqlite，纯 Go）
- 内存 Session + bcrypt 密码哈希

templates/home.html

@@ -0,0 +1,39 @@
+{{define "home.html"}}
+{{template "header" .}}
+<div class="home-container{{if .BackgroundImage}} has-background{{end}}"{{if .BackgroundImage}} style="background-image: url('{{.BackgroundImage}}?thumb=1'); background-size: cover; background-position: center; background-attachment: fixed;"{{end}}>
+    <header class="home-header">
+        <h1 class="home-title">{{.SiteTitle}}</h1>
+        {{if .SiteSubtitle}}<p class="site-subtitle">{{.SiteSubtitle}}</p>{{else}}<p class="home-subtitle">快速导航，一键直达</p>{{end}}
+    </header>
+
+    <div class="search-box">
+        <form id="search-form" action="/search" method="GET">
+            <input type="text" id="search-input" name="q" class="search-input" placeholder="搜索..." autofocus>
+            <button type="submit" class="search-btn">搜索</button>
+        </form>
+    </div>
+
+    <div class="card-grid">
+        {{range .Cards}}
+        <a href="/click/{{.ID}}" class="card-item" target="_blank" rel="noopener noreferrer">
+            <div class="card-icon">{{if .Icon}}{{if hasPrefix .Icon "/uploads/"}}<img src="{{.Icon}}?thumb=1" alt="{{.Title}}" class="card-icon-img">{{else}}<span class="card-emoji">{{.Icon}}</span>{{end}}{{else}}<span class="card-emoji">🔗</span>{{end}}</div>
+            <div class="card-content">
+                <div class="card-title">{{.Title}}</div>
+                {{if .Subtitle}}<div class="card-subtitle">{{.Subtitle}}</div>{{end}}
+            </div>
+        </a>
+        {{end}}
+    </div>
+
+    <footer class="home-footer">
+        <a href="/admin/login">管理后台</a>
+    </footer>
+</div>
+
+<script>
+document.addEventListener('DOMContentLoaded', function() {
+    document.getElementById('search-input').focus();
+});
+</script>
+{{template "footer" .}}
+{{end}}