Refactor provider composition with DataProviders wrapper

Encapsulated `EventsProvider` and `EventThemesProvider` into a new `DataProviders` component to simplify and modularize provider structure. Updated the root provider hierarchy to use `DataProviders`, improving maintainability and readability.

frontend/src/providers/data.tsx

@@ -0,0 +1,11 @@
+import React from "react";
+import { EventsProvider } from "@/context/event-context";
+import { EventThemesProvider } from "@/context/event-theme-context";
+
+export function DataProviders({ children }: { children: React.ReactNode }) {
+  return (
+    <EventThemesProvider>
+      <EventsProvider>{children}</EventsProvider>;
+    </EventThemesProvider>
+  );
+}

frontend/src/providers/index.tsx

@@ -1,11 +1,11 @@
 "use client";
 
 import React from "react";
-import { QueryClientProvider, QueryClient } from "@tanstack/react-query";
+import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
 import { ReactQueryDevtools } from "@tanstack/react-query-devtools";
 import { AuthProvider } from "@/context/auth-context";
-import { EventsProvider } from "@/context/event-context";
 import { ThemeProvider } from "next-themes";
+import { DataProviders } from "@/providers/data";
 
 // Create a client
 const queryClient = new QueryClient({
@@ -28,7 +28,7 @@ export function Providers({ children }: { children: React.ReactNode }) {
         disableTransitionOnChange
       >
         <AuthProvider>
-          <EventsProvider>{children}</EventsProvider>
+          <DataProviders>{children}</DataProviders>
         </AuthProvider>
       </ThemeProvider>
       <ReactQueryDevtools initialIsOpen={false} />