chore(deps): update nextjs monorepo to v15

src/client/package.json

@@ -12,7 +12,7 @@
     "@reduxjs/toolkit": "2.3.0",
     "@tippyjs/react": "4.2.6",
     "axios": "1.7.7",
-    "next": "14.2.15",
+    "next": "15.0.0",
     "next-pwa": "5.6.0",
     "react": "18.3.1",
     "react-dom": "18.3.1",
@@ -26,7 +26,7 @@
     "autoprefixer": "10.4.20",
     "cssnano": "7.0.6",
     "eslint": "9.13.0",
-    "eslint-config-next": "14.2.15",
+    "eslint-config-next": "15.0.0",
     "postcss": "8.4.47",
     "postcss-import": "16.1.0",
     "prettier": "3.3.3",