feat(ui): 统一登录与会话页的 shadcn 交互组件

登录页切换为官方 input-group 组合并将全站提示从 antd message 统一为 sonner toast，确保通知位置与风格一致。同时补齐相关 shadcn CLI 生成组件及构建配置更新。

Co-authored-by: Cursor <cursoragent@cursor.com>

components.json

@@ -0,0 +1,25 @@
+{
+  "$schema": "https://ui.shadcn.com/schema.json",
+  "style": "radix-nova",
+  "rsc": false,
+  "tsx": true,
+  "tailwind": {
+    "config": "",
+    "css": "src/index.css",
+    "baseColor": "neutral",
+    "cssVariables": true,
+    "prefix": ""
+  },
+  "iconLibrary": "lucide",
+  "rtl": false,
+  "aliases": {
+    "components": "@/components",
+    "utils": "@/lib/utils",
+    "ui": "@/components/ui",
+    "lib": "@/lib",
+    "hooks": "@/hooks"
+  },
+  "menuColor": "default",
+  "menuAccent": "subtle",
+  "registries": {}
+}