chore: resolve high-severity npm audit advisories

The dependency-audit CI step (npm audit --audit-level=high) was failing
on pre-existing transitive advisories. Force patched versions via
overrides and bump vite to a patched 7.x:

- esbuild ^0.28.1  (GHSA-g7r4-m6w7-qqqr, high)
- form-data ^4.0.6 (GHSA-hmw2-7cc7-3qxx, high)
- vite ^7.3.5      (GHSA-v6wh-96g9-6wx3 / GHSA-fx2h-pf6j-xcff, high)

Audit now passes at --audit-level=high (only a low @babel/core and
moderate js-yaml remain, both below the gate and build/dev-time only;
js-yaml is a direct dep so it can't be overridden). Build + full test
suite (1130) green on the bumped toolchain.

ha-relevant: no

frontend/package.json

@@ -38,7 +38,9 @@
     "zustand": "^5.0.11"
   },
   "overrides": {
-    "hono": "^4.12.21"
+    "hono": "^4.12.21",
+    "esbuild": "^0.28.1",
+    "form-data": "^4.0.6"
   },
   "devDependencies": {
     "@eslint/js": "^9.39.1",
@@ -61,7 +63,7 @@
     "tailwindcss": "^4.2.1",
     "typescript": "~5.9.3",
     "typescript-eslint": "^8.48.0",
-    "vite": "^7.3.1",
+    "vite": "^7.3.5",
     "vitest": "^4.0.18"
   }
 }