feat: 恢复导航栏完整功能（通知/导出/导入）

- 两个页面 header 统一添加：通知铃铛、导出按钮、导入按钮、用户信息
- 添加通知相关 JS 函数到 analysis.html
- 添加导出/导入相关 JS 函数到 analysis.html
- 导航栏布局：Logo + 标题 | 首页/分析 | 用户名+通知+导出+导入+管理+退出

frontend/index.html

@@ -36,13 +36,43 @@ body{font-family:-apple-system,BlinkMacSystemFont,"SF Pro Display","SF Pro Text"
 .nav-tab{padding:7px 20px;border-radius:6px;font-size:13px;font-weight:500;color:var(--text2);text-decoration:none;transition:all .2s;cursor:pointer;white-space:nowrap}
 .nav-tab:hover{color:var(--text);background:rgba(255,255,255,.5)}
 .nav-tab.active{background:#fff;color:var(--text);box-shadow:0 1px 4px rgba(0,0,0,.08)}
-.header-right{display:flex;align-items:center;gap:6px;flex-shrink:0}
-.header-right a{color:var(--text2);text-decoration:none;font-size:12px;padding:6px 14px;border-radius:var(--radius-xs);transition:all .2s;white-space:nowrap}
-.header-right a:hover{background:rgba(0,0,0,.04);color:var(--text)}
+.header-right a,.hdr-btn{color:var(--text2);text-decoration:none;font-size:12px;padding:6px 14px;border-radius:var(--radius-xs);transition:all .2s;background:transparent;border:none;cursor:pointer;font-family:inherit}
+.header-right a:hover,.hdr-btn:hover{background:rgba(0,0,0,.04);color:var(--text)}
 .header-right .admin-link{color:var(--blue);font-weight:500}
 .header-right .logout-link{color:var(--red)}
 .user-info{color:var(--text);font-size:13px;font-weight:500;cursor:pointer;padding:6px 14px;border-radius:var(--radius-xs);transition:all .2s;background:rgba(0,0,0,.02)}
 .user-info:hover{background:rgba(0,0,0,.06)}
+.notif-wrap{position:relative}
+.notif-bell{cursor:pointer;padding:6px 8px;border-radius:var(--radius-xs);transition:all .2s;color:var(--text2)}
+.notif-bell:hover{background:rgba(0,0,0,.04);color:var(--text)}
+.notif-badge{position:absolute;top:2px;right:2px;min-width:16px;height:16px;background:var(--red);color:#fff;border-radius:8px;font-size:10px;font-weight:600;display:flex;align-items:center;justify-content:center;padding:0 4px}
+.notif-dropdown{display:none;position:absolute;right:0;top:calc(100% + 8px);background:rgba(255,255,255,.96);backdrop-filter:blur(24px);border:1px solid var(--border);border-radius:var(--radius);box-shadow:0 12px 48px rgba(0,0,0,.15);width:360px;max-height:480px;overflow:hidden;z-index:60}
+.notif-dropdown.show{display:block}
+.notif-header{padding:14px 16px;border-bottom:1px solid var(--border);display:flex;justify-content:space-between;align-items:center}
+.notif-header h4{font-size:14px;font-weight:600;color:var(--text)}
+.notif-header .mark-all{font-size:12px;color:var(--blue);cursor:pointer;background:none;border:none;font-family:inherit}
+.notif-header .mark-all:hover{text-decoration:underline}
+.notif-list{overflow-y:auto;max-height:380px}
+.notif-item{padding:12px 16px;border-bottom:1px solid var(--border);cursor:pointer;transition:background .15s;display:flex;gap:12px;align-items:flex-start}
+.notif-item:hover{background:rgba(0,0,0,.02)}
+.notif-item.unread{background:rgba(0,113,227,.03)}
+.notif-item .notif-icon{width:32px;height:32px;border-radius:8px;display:flex;align-items:center;justify-content:center;font-size:16px;flex-shrink:0}
+.notif-icon.repayment_due{background:rgba(0,113,227,.08)}
+.notif-icon.repayment_overdue{background:rgba(255,59,48,.08)}
+.notif-icon.system{background:rgba(175,82,222,.08)}
+.notif-icon.account{background:rgba(52,199,89,.08)}
+.notif-item .notif-content{flex:1;min-width:0}
+.notif-item .notif-title{font-size:13px;font-weight:500;color:var(--text);margin-bottom:2px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
+.notif-item .notif-msg{font-size:12px;color:var(--text3);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
+.notif-item .notif-time{font-size:11px;color:var(--text3);white-space:nowrap}
+.notif-empty{text-align:center;padding:32px;color:var(--text3);font-size:13px}
+.export-wrap{position:relative}
+.export-menu{display:none;position:absolute;right:0;top:calc(100% + 4px);background:rgba(255,255,255,.95);backdrop-filter:blur(20px);border:1px solid var(--border);border-radius:var(--radius-sm);box-shadow:0 8px 32px rgba(0,0,0,.12);min-width:160px;z-index:50;overflow:hidden}
+.export-menu.show{display:block}
+.export-menu a{display:block;padding:10px 18px;font-size:13px;color:var(--text);text-decoration:none;transition:background .15s}
+.export-menu a:hover{background:rgba(0,0,0,.04)}
+.user-info{color:var(--text);font-size:13px;font-weight:500;cursor:pointer;padding:6px 14px;border-radius:var(--radius-xs);transition:all .2s;background:rgba(0,0,0,.02)}
+.user-info:hover{background:rgba(0,0,0,.06)}
 
 /* MAIN */
 .main{max-width:1120px;margin:0 auto;padding:24px;display:grid;grid-template-columns:320px 1fr;gap:20px}
@@ -337,6 +367,31 @@ body{font-family:-apple-system,BlinkMacSystemFont,"SF Pro Display","SF Pro Text"
     </div>
     <div class="header-right">
       <span class="user-info" id="userInfo"></span>
+      <div class="notif-wrap" style="position:relative">
+        <div class="notif-bell" onclick="toggleNotifDropdown(event)">
+          <svg width="18" height="18" viewBox="0 0 24 24" fill="currentColor"><path d="M12 22c1.1 0 2-.9 2-2h-4c0 1.1.9 2 2 2zm6-6v-5c0-3.07-1.63-5.64-4.5-6.32V4c0-.83-.67-1.5-1.5-1.5s-1.5.67-1.5 1.5v.68C7.64 5.36 6 7.92 6 11v5l-2 2v1h16v-1l-2-2z"/></svg>
+          <span class="notif-badge" id="notifBadge" style="display:none">0</span>
+        </div>
+        <div class="notif-dropdown" id="notifDropdown">
+          <div class="notif-header"><h4>通知</h4><button class="mark-all" onclick="markAllNotifRead()">全部已读</button></div>
+          <div class="notif-list" id="notifList"><div class="notif-empty">暂无通知</div></div>
+        </div>
+      </div>
+      <div class="export-wrap">
+        <button class="hdr-btn" onclick="toggleExport(event)">导出</button>
+        <div class="export-menu" id="exportMenu">
+          <a href="#" onclick="exportCSV(event)">导出 CSV</a>
+          <a href="#" onclick="exportJSON(event)">导出 JSON</a>
+          <a href="#" onclick="exportHTML(event)">导出 HTML</a>
+        </div>
+      </div>
+      <div class="export-wrap">
+        <button class="hdr-btn" onclick="toggleImport(event)">导入</button>
+        <div class="export-menu" id="importMenu">
+          <a href="#" onclick="downloadTemplate(event)">下载模板</a>
+          <a href="#" onclick="showImportModal(event)">导入 CSV</a>
+        </div>
+      </div>
       <a href="/admin.html" class="admin-link" id="adminLink" style="display:none">管理</a>
       <a href="#" class="logout-link" onclick="doLogout()">退出</a>
     </div>