Add local background removal and mask tools

nginx.conf

@@ -8,6 +8,11 @@ server {
   server_tokens off;
   access_log off;
 
+  # Enable SharedArrayBuffer so ONNX Runtime can use multithreaded WASM when
+  # WebGPU is unavailable or falls back to CPU execution.
+  add_header Cross-Origin-Opener-Policy "same-origin" always;
+  add_header Cross-Origin-Embedder-Policy "require-corp" always;
+
   gzip on;
   gzip_comp_level 6;
   gzip_min_length 1024;