fix(deps): drop invalid create-ecdh override (max version is 4.x not 5.x)

The earlier npm override 'create-ecdh: ^5.0.1' resolved to no version on
the registry. CI install failed with ETARGET. Removing the override —
elliptic override alone covers the high-severity transitive vulns.
Remaining 6 lows in vite-plugin-node-polyfills chain accepted.

web/package.json

@@ -121,8 +121,7 @@
     "@pezkuwi/x-textencoder": "^14.0.25",
     "@pezkuwi/x-ws": "^14.0.25",
     "@pezkuwi/networks": "^14.0.25",
-    "elliptic": "^6.6.1",
-    "create-ecdh": "^5.0.1"
+    "elliptic": "^6.6.1"
   },
   "devDependencies": {
     "@eslint/js": "^9.9.0",