build(config): add custom externals mapping for @napi-rs/canvas in server webpack

Configure webpack to treat @napi-rs/canvas as an external dependency under
the 'canvas' module name when building the server bundle. This adjustment
ensures proper module resolution and avoids bundling native dependencies
directly, improving deployment reliability for environments requiring
@napi-rs/canvas.

next.config.ts

@@ -80,6 +80,14 @@ const nextConfig: NextConfig = {
     ],
   },
   webpack: (config, { isServer }) => {
+    if (isServer) {
+      config.externals = [
+        ...(config.externals || []),
+        {
+          canvas: 'commonjs @napi-rs/canvas',
+        },
+      ];
+    }
     if (isServer && bundleWorkerCompute) {
       config.resolve.alias = {
         ...(config.resolve.alias || {}),