refactor(vscode-ide-companion): 重构 WebViewProvider 初始化逻辑

- 抽离初始化代理连接逻辑到单独的方法中
- 优化面板恢复时的代理连接流程
- 移除 EmptyState 组件中的信息横幅
- 在 App 组件中添加可关闭的信息横幅
- 调整输入表单样式，移除冗余样式

packages/vscode-ide-companion/src/webview/components/EmptyState.css

@@ -46,74 +46,3 @@
   font-weight: 400;
   max-width: 400px;
 }
-
-/* Banner Styles */
-.empty-state-banner {
-  display: flex;
-  align-items: center;
-  justify-content: space-between;
-  gap: 12px;
-  padding: 12px 16px;
-  background-color: var(--app-input-secondary-background);
-  border: 1px solid var(--app-primary-border-color);
-  border-radius: var(--corner-radius-medium);
-  width: 100%;
-  max-width: 500px;
-}
-
-.banner-content {
-  display: flex;
-  align-items: center;
-  gap: 12px;
-  flex: 1;
-  min-width: 0;
-}
-
-.banner-icon {
-  flex-shrink: 0;
-  width: 16px;
-  height: 16px;
-  fill: var(--app-primary-foreground);
-}
-
-.banner-content label {
-  font-size: 13px;
-  color: var(--app-primary-foreground);
-  margin: 0;
-  line-height: 1.4;
-}
-
-.banner-link {
-  color: var(--app-claude-orange);
-  text-decoration: none;
-  cursor: pointer;
-}
-
-.banner-link:hover {
-  text-decoration: underline;
-}
-
-.banner-close {
-  flex-shrink: 0;
-  width: 20px;
-  height: 20px;
-  padding: 0;
-  background: transparent;
-  border: none;
-  border-radius: var(--corner-radius-small);
-  color: var(--app-primary-foreground);
-  cursor: pointer;
-  display: flex;
-  align-items: center;
-  justify-content: center;
-  transition: background-color 0.2s;
-}
-
-.banner-close:hover {
-  background-color: var(--app-ghost-button-hover-background);
-}
-
-.banner-close svg {
-  width: 10px;
-  height: 10px;
-}