chore: 统一本地服务器与远程仓库源码

- 合并 main 与 master 历史并以服务器结构为基线
- 保留迁移、数据保留、AWS 账单与部署安全能力
- 建立 SDD 规格和 CI 验证闭环

frontend/src/index.css

@@ -668,6 +668,94 @@
     margin-top: auto;
   }
 
+  /* ===== 手机端布局：抽屉导航与紧凑内容节奏 // Logan.Li ===== */
+  .dg-mobile-nav-backdrop {
+    display: none;
+  }
+
+  @media (max-width: 767px) {
+    :root,
+    [data-theme] {
+      --layout-page-padding-x: 1rem;
+      --layout-page-padding-y: 1rem;
+      --layout-breadcrumb-gap: 0.75rem;
+    }
+
+    .dg-app-shell {
+      overflow-x: clip;
+    }
+    body.dg-mobile-nav-open {
+      overflow: hidden;
+    }
+    .dg-app-workspace,
+    .dg-app-header {
+      margin-left: 0 !important;
+    }
+    .dg-sidebar {
+      width: min(86vw, 20rem) !important;
+      transform: translateX(-100%);
+      box-shadow: var(--shadow-dropdown);
+      transition: transform 0.25s ease;
+    }
+    .dg-sidebar[data-mobile-open='true'] {
+      transform: translateX(0);
+    }
+    .dg-mobile-nav-backdrop {
+      display: block;
+      position: fixed;
+      inset: 0;
+      z-index: 35;
+      border: 0;
+      background: var(--dg-overlay);
+      opacity: 0;
+      pointer-events: none;
+      transition: opacity 0.25s ease;
+    }
+    .dg-sidebar[data-mobile-open='true'] + .dg-mobile-nav-backdrop {
+      opacity: 1;
+      pointer-events: auto;
+    }
+    .dg-app-breadcrumb {
+      min-width: 0;
+    }
+    .dg-app-content {
+      overflow-x: hidden;
+    }
+    .dg-app-footer {
+      display: none;
+    }
+    .dg-page {
+      gap: 1rem;
+      min-width: 0;
+    }
+    .dg-page-header {
+      align-items: flex-start;
+      gap: 0.75rem;
+    }
+    .dg-page-title {
+      font-size: 1.5rem;
+      line-height: 2rem;
+    }
+    .dg-page-actions {
+      width: 100%;
+    }
+    .dg-page-toolbar,
+    .dg-content-panel-toolbar {
+      align-items: stretch;
+      gap: 0.75rem;
+    }
+    .dg-content-panel-toolbar {
+      padding: 0.75rem;
+    }
+    .dg-page-tabs {
+      overflow-x: auto;
+      scrollbar-width: none;
+    }
+    .dg-page-tabs::-webkit-scrollbar {
+      display: none;
+    }
+  }
+
   /* ===== Page Container ===== */
   .dg-page {
     gap: var(--space-page);