refactor: enhance Sidebar component with Better Auth integration

- Replaced the use of `useConvexClient` with `useQuery` for fetching the current user.
- Updated avatar URL retrieval to utilize the current user data from Better Auth.
- Refactored login and logout functions to use the new `authClient` methods for improved authentication flow.
- Cleaned up the component structure and styling for better readability and maintainability.
- Adjusted sidebar and footer styles for consistency with the new design system.

packages/backend/convex/auth.ts

@@ -50,10 +50,21 @@ export const getCurrentUser = query({
       .query("usuarios")
       .withIndex("authId", (q) => q.eq("authId", authUser._id))
       .unique();
+
     if (!user) {
       return;
     }
-    return user;
+
+    if (!user.roleId) {
+      return { ...user, role: null };
+    }
+
+    const role = await ctx.db
+      .query("roles")
+      .withIndex("by_id", (q) => q.eq("_id", user.roleId))
+      .unique();
+
+    return { ...user, role };
   },
 });