deps: next 16.3.4, eslint-config-next 16.3.4

Patch bump within the 16.3 line. Follow-up to 16.3.3 security release; restores AVIF Image Optimization and backports a few build/testmode fixes.

package.json

@@ -12,7 +12,7 @@
   "dependencies": {
     "@chakra-ui/react": "^3.32.0",
     "@emotion/react": "^11.14.0",
-    "next": "16.3.3",
+    "next": "16.3.4",
     "next-themes": "^0.4.6",
     "react": "19.2.8",
     "react-dom": "19.2.8",
@@ -24,7 +24,7 @@
     "@types/react": "^19",
     "@types/react-dom": "^19",
     "eslint": "^9",
-    "eslint-config-next": "16.3.3",
+    "eslint-config-next": "16.3.4",
     "tailwindcss": "^4",
     "typescript": "^5"
   },