security: pin axios to 1.14.0 to prevent supply chain attack

Axios versions 1.14.1 and 0.30.4 were compromised on March 31, 2026
with a RAT dropper attributed to North Korean threat actor. Pin to
exact 1.14.0 (latest safe release) to prevent resolution to compromised
versions. See https://github.com/axios/axios/issues/10604

frontend/package.json

@@ -24,7 +24,7 @@
     "@types/dompurify": "^3.0.5",
     "@types/lodash": "^4.17.20",
     "@types/react-google-recaptcha": "^2.1.9",
-    "axios": "^1.12.2",
+    "axios": "1.14.0",
     "clsx": "^2.0.0",
     "date-fns": "4.1.0",
     "dompurify": "^3.2.6",