style(top-bar): 给顶部状态栏标题区添加背景条以区分视觉层次

- 顶部状态栏 `.top-bar__title` 增加品牌色淡底背景和左侧主色竖条
- 文字颜色调整为深色，保持搜索框可读性
- 调整主题相关样式，处理 light 主题和 dark 主题下背景条效果差异
- 优化多个主题下 Logo 背景和文字颜色，提升整体视觉一致性
- 修改欢迎页背景颜色及相关元素颜色，增强视觉层次感
- 调整部分组件和布局的内边距与边框颜色，提升界面细节表现
- 隐藏顶部主题切换项，调整 hover 背景颜色以适应新视觉风格

src/views/wel/index.vue

@@ -311,12 +311,12 @@ export default {
   display: flex;
   align-items: center;
   justify-content: space-between;
-  background: linear-gradient(135deg, #409eff 0%, #1677ff 50%, #0958d9 100%);
+  background: #ffffff;
   border-radius: 12px;
   padding: 26px 30px;
-  color: #fff;
+  color: #303133;
   margin-bottom: 16px;
-  box-shadow: 0 6px 24px rgba(64, 158, 255, 0.3);
+  box-shadow: 0 6px 24px rgba(0, 0, 0, 0.08);
   position: relative;
   overflow: hidden;
 }
@@ -331,27 +331,27 @@ export default {
 .wel-banner__circle {
   position: absolute;
   border-radius: 50%;
-  background: rgba(255, 255, 255, 0.07);
+  background: rgba(115, 209, 61, 0.07);
   &--1 {
     width: 200px;
     height: 200px;
     right: -40px;
     top: -60px;
-    background: rgba(255, 255, 255, 0.1);
+    background: rgba(115, 209, 61, 0.1);
   }
   &--2 {
     width: 140px;
     height: 140px;
     right: 120px;
     bottom: -50px;
-    background: rgba(255, 255, 255, 0.06);
+    background: rgba(115, 209, 61, 0.06);
   }
   &--3 {
     width: 80px;
     height: 80px;
     left: 25%;
     top: -20px;
-    background: rgba(255, 255, 255, 0.05);
+    background: rgba(115, 209, 61, 0.05);
   }
 }
 .wel-banner__dot-grid {
@@ -366,9 +366,9 @@ export default {
     width: 5px;
     height: 5px;
     border-radius: 50%;
-    background: rgba(255, 255, 255, 0.2);
-    &:nth-child(3n) { background: rgba(255, 255, 255, 0.35); }
-    &:nth-child(3n + 1) { background: rgba(255, 255, 255, 0.12); }
+    background: rgba(115, 209, 61, 0.2);
+    &:nth-child(3n) { background: rgba(115, 209, 61, 0.35); }
+    &:nth-child(3n + 1) { background: rgba(115, 209, 61, 0.12); }
   }
 }
 .wel-banner__left {
@@ -382,7 +382,8 @@ export default {
   width: 56px;
   height: 56px;
   border-radius: 50%;
-  background: rgba(255, 255, 255, 0.2);
+  background: rgba(115, 209, 61, 0.15);
+  color: #389e0d;
   display: flex;
   align-items: center;
   justify-content: center;