refactor: Simplify Discord API response handling and define response interface

src/app/api/upload-part/route.ts

@@ -10,6 +10,15 @@ if (!process.env.DISCORD_BOT_TOKEN || !process.env.DISCORD_CHANNEL_ID) {
 
 const rateLimiter = new DiscordRateLimiter(DISCORD_API_BASE_URL, process.env.DISCORD_BOT_TOKEN);
 
+interface DiscordMessageResponse {
+  id: string;
+  attachments: Array<{
+    id: string;
+    url: string;
+    size: number;
+  }>;
+}
+
 export async function POST(request: Request) {
   try {
     const formData = await request.formData();
@@ -25,26 +34,13 @@ export async function POST(request: Request) {
     const discordFormData = new FormData();
     discordFormData.append('file', chunk, `chunk-${partIndex}.bin`);
 
-    const discordRes: Response = await rateLimiter.request(
+    const discordData = await rateLimiter.request<DiscordMessageResponse>(
       `/channels/${process.env.DISCORD_CHANNEL_ID}/messages`,
       {
         method: 'POST',
         body: discordFormData,
       }
     );
-
-    let discordData;
-    try {
-      discordData = await discordRes.json();
-    } catch (jsonError) {
-      console.error('Failed to parse Discord response as JSON:', jsonError);
-      return NextResponse.json({ error: 'Failed to parse Discord response' }, { status: 500 });
-    }
-
-    if (!discordRes.ok) {
-      console.error('Discord API Error:', discordData);
-      return NextResponse.json({ error: 'Failed to upload to Discord' }, { status: 500 });
-    }
     const attachment = discordData.attachments[0];
 
     if (!attachment) {