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/admin/access_logs.html

@@ -0,0 +1,97 @@
+{{define "admin/access_logs.html"}}
+{{template "header" .}}
+<div class="admin-layout">
+    <nav class="admin-nav">
+        <div class="admin-nav-brand">Portal 管理</div>
+        <div class="admin-nav-links">
+            <a href="/admin" class="admin-nav-link">首页</a>
+            <a href="/admin/cards" class="admin-nav-link">卡片管理</a>
+            <a href="/admin/access-logs" class="admin-nav-link active">访问日志</a>
+            <a href="/admin/logs" class="admin-nav-link">登录日志</a>
+            <a href="/admin/ip-whitelist" class="admin-nav-link">IP白名单</a>
+            <a href="/admin/settings" class="admin-nav-link">设置</a>
+            <a href="/admin/password" class="admin-nav-link">修改密码</a>
+        </div>
+        <div class="admin-nav-user">
+            <span>{{.Username}}</span>
+            <form method="POST" action="/admin/logout" style="display:inline">
+                <button type="submit" class="btn btn-sm btn-secondary">退出</button>
+            </form>
+        </div>
+    </nav>
+    <main class="admin-main">
+        <h1>访问日志</h1>
+
+        <!-- 筛选表单 -->
+        <form class="filter-form" method="GET" action="/admin/access-logs">
+            <div class="filter-row">
+                <div class="filter-group">
+                    <label>IP地址</label>
+                    <input type="text" name="ip" value="{{.FilterIP}}" placeholder="搜索IP...">
+                </div>
+                <div class="filter-group">
+                    <label>动作类型</label>
+                    <select name="action">
+                        <option value="">全部</option>
+                        <option value="visit" {{if eq .FilterAction "visit"}}selected{{end}}>访问</option>
+                        <option value="click" {{if eq .FilterAction "click"}}selected{{end}}>点击</option>
+                        <option value="search" {{if eq .FilterAction "search"}}selected{{end}}>搜索</option>
+                    </select>
+                </div>
+                <div class="filter-group filter-actions-group">
+                    <button type="submit" class="btn btn-primary btn-sm">筛选</button>
+                    <a href="/admin/access-logs" class="btn btn-secondary btn-sm">重置</a>
+                </div>
+            </div>
+        </form>
+
+        <table class="admin-table">
+            <thead>
+                <tr>
+                    <th>时间</th>
+                    <th>IP地址</th>
+                    <th>类型</th>
+                    <th>详情</th>
+                    <th>来源</th>
+                    <th>客户端</th>
+                </tr>
+            </thead>
+            <tbody>
+                {{range .Logs}}
+                <tr>
+                    <td>{{.CreatedAt.Format "2006-01-02 15:04:05"}}</td>
+                    <td><code>{{.IP}}</code></td>
+                    <td>
+                        {{if eq .ActionType "visit"}}<span class="badge badge-success">访问</span>
+                        {{else if eq .ActionType "click"}}<span class="badge badge-primary">点击</span>
+                        {{else if eq .ActionType "search"}}<span class="badge badge-warning">搜索</span>
+                        {{else}}<span class="badge badge-secondary">{{.ActionType}}</span>{{end}}
+                    </td>
+                    <td class="detail-cell" title="{{.Detail}}">{{if .Detail}}{{.Detail}}{{else}}—{{end}}</td>
+                    <td class="ua-cell" title="{{.Referer}}">{{if .Referer}}<a href="{{.Referer}}" target="_blank">来源</a>{{else}}—{{end}}</td>
+                    <td class="ua-cell" title="{{.UserAgent}}">{{.UserAgent}}</td>
+                </tr>
+                {{end}}
+                {{if not .Logs}}
+                <tr>
+                    <td colspan="6" style="text-align:center;color:#999;">暂无访问日志</td>
+                </tr>
+                {{end}}
+            </tbody>
+        </table>
+
+        {{if gt .TotalPages 1}}
+        <div class="pagination">
+            {{if gt .Page 1}}
+            <a href="/admin/access-logs?page={{sub .Page 1}}&ip={{.FilterIP}}&action={{.FilterAction}}" class="btn btn-sm btn-secondary">上一页</a>
+            {{end}}
+            <span class="pagination-info">第 {{.Page}} / {{.TotalPages}} 页（共 {{.Total}} 条）</span>
+            {{if lt .Page .TotalPages}}
+            <a href="/admin/access-logs?page={{add .Page 1}}&ip={{.FilterIP}}&action={{.FilterAction}}" class="btn btn-sm btn-secondary">下一页</a>
+            {{end}}
+        </div>
+        {{end}}
+    </main>
+</div>
+{{template "footer" .}}
+{{end}}