Pin oxlint to ~1.60.0 to match eslint-plugin-oxlint peer range

eslint-plugin-oxlint@1.60.0 has a strict peerDependency of
oxlint@~1.60.0, and 1.61.0 is not yet released. Keep the two in
lockstep so npm install resolves cleanly.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

frontend/package.json

@@ -45,7 +45,7 @@
     "msw": "^2.12.10",
     "npm-run-all2": "^8.0.4",
     "openapi-typescript": "^7.13.0",
-    "oxlint": "~1.61.0",
+    "oxlint": "~1.60.0",
     "prettier": "3.8.1",
     "typescript": "~5.9.3",
     "vite": "^8.0.0",