Remove hardcoded DNS — keep host resolv.conf in rootfs

Don't overwrite the host's resolv.conf with hardcoded 8.8.8.8.
The host's DNS config is already correct for both build and runtime.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/setup.ts

@@ -115,11 +115,6 @@ EOF`);
         { stdio: "inherit", timeout: 120_000 }
       );
 
-      // Set static DNS for runtime (replace host resolv.conf used during install)
-      execSync(
-        `echo "nameserver 8.8.8.8" | sudo tee ${ext4Mount}/etc/resolv.conf > /dev/null`
-      );
-
       // Networking init script
       execSync(`sudo tee ${ext4Mount}/etc/init.d/networking > /dev/null << 'EOF'
 #!/sbin/openrc-run