perf: skip Next.js image re-optimization and stream proxy responses

Thumbnails are already optimized (WebP) by the API, so disable Next.js
image optimization to avoid redundant CPU work. Switch route handlers
from buffering (arrayBuffer) to streaming (response.body) to reduce
memory usage and latency.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/backoffice/app/api/books/[bookId]/pages/[pageNum]/route.ts

@@ -28,12 +28,9 @@ export async function GET(
       });
     }
 
-    // Récupérer le content-type et les données
     const contentType = response.headers.get("content-type") || "image/webp";
-    const imageBuffer = await response.arrayBuffer();
 
-    // Retourner l'image avec le bon content-type
-    return new NextResponse(imageBuffer, {
+    return new NextResponse(response.body, {
       headers: {
         "Content-Type": contentType,
         "Cache-Control": "public, max-age=300",

apps/backoffice/app/api/books/[bookId]/thumbnail/route.ts

@@ -20,9 +20,8 @@ export async function GET(
     }
 
     const contentType = response.headers.get("content-type") || "image/webp";
-    const imageBuffer = await response.arrayBuffer();
 
-    return new NextResponse(imageBuffer, {
+    return new NextResponse(response.body, {
       headers: {
         "Content-Type": contentType,
         "Cache-Control": "public, max-age=31536000, immutable",

apps/backoffice/next.config.mjs

@@ -4,6 +4,7 @@ const nextConfig = {
   typedRoutes: true,
   images: {
     minimumCacheTTL: 86400,
+    unoptimized: true,
   },
 };