fix: stub @solana/web3.js in webpack (connector compat layer)

app/next.config.ts

@@ -3,6 +3,17 @@ import type { NextConfig } from 'next'
 const config: NextConfig = {
   reactStrictMode: true,
   transpilePackages: ['@solana/connector'],
+  // @solana/connector bundles a web3.js v1 compat layer for legacy wallets.
+  // We never pass web3.js Transaction objects (we use @solana/kit / Uint8Array),
+  // so this code path is dead. Stub the module so webpack doesn't error at build
+  // time when it can't resolve the optional dynamic import('@solana/web3.js').
+  webpack: (webpackConfig) => {
+    webpackConfig.resolve.fallback = {
+      ...webpackConfig.resolve.fallback,
+      '@solana/web3.js': false,
+    }
+    return webpackConfig
+  },
 }
 
 export default config