feat: update environment variables for development and production; add user store and authentication client

- Updated VITE_API_URL in .env.development to point to local server.
- Retained VITE_API_URL in .env.production for production use.
- Added user store for managing user profile and authentication state.
- Created authentication client for handling user login and token management.
- Introduced safeClient utility for making API requests with error handling.
- Updated various components and views to utilize new user store and authentication logic.
- Enhanced UI styles for better visual consistency across the application.

src/auth/index.ts

@@ -0,0 +1,16 @@
+import { usernameClient } from "better-auth/client/plugins";
+import { createAuthClient } from "better-auth/vue";
+
+const baseURL = import.meta.env.DEV ? window.location.origin : import.meta.env.VITE_API_URL;
+
+export const authClient = createAuthClient({
+  baseURL,
+  fetchOptions: {
+    credentials: "include",
+    auth: {
+      type: "Bearer",
+      token: () => localStorage.getItem("user-token") || "",
+    },
+  },
+  plugins: [usernameClient()],
+});