fix: force onnxruntime-web@1.18.0 via resolutions to eliminate nested 1.24.3

vad-web's own dependency was resolved to ort@1.24.3 (nested in its
node_modules), which only has threaded WASM requiring a .mjs dynamic
import that Vite fails to serve correctly. Pin ort to 1.18.0 via yarn
resolutions so all packages share the same copy with ort-wasm-simd.wasm
(non-threaded SIMD). Also remove the now-unnecessary COOP/COEP headers.

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

vite.config.ts

@@ -118,11 +118,6 @@ export default ({
         key: fs.readFileSync("./backend/dev_tls_m.localhost.key"),
         cert: fs.readFileSync("./backend/dev_tls_m.localhost.crt"),
       },
-      // Required for SharedArrayBuffer (used by onnxruntime-web threaded WASM)
-      headers: {
-        "Cross-Origin-Opener-Policy": "same-origin",
-        "Cross-Origin-Embedder-Policy": "require-corp",
-      },
     },
     worker: {
       format: "es",