security: next 16.2.4 -> 16.2.12, postcss/sharp override

dev'de dogrulanip production'a alindi. npm audit: 5 HIGH -> 0.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

package.json

@@ -8,10 +8,15 @@
     "start": "next start",
     "lint": "eslint"
   },
+  "comment_overrides": "next'in icine gomulu postcss/sharp HIGH acikli (GHSA-r28c-9q8g-f849 dosya okuma, GHSA-f88m-g3jw-g9cj libvips). next kendi bagimliligini guncelleyene kadar override ile zorluyoruz — 2026-08-01",
+  "overrides": {
+    "postcss": "^8.5.18",
+    "sharp": "^0.35.3"
+  },
   "dependencies": {
     "gray-matter": "^4.0.3",
     "marked": "^18.0.2",
-    "next": "16.2.4",
+    "next": "16.2.12",
     "react": "19.2.4",
     "react-dom": "19.2.4"
   },
@@ -21,7 +26,7 @@
     "@types/react": "^19",
     "@types/react-dom": "^19",
     "eslint": "^9",
-    "eslint-config-next": "16.2.4",
+    "eslint-config-next": "16.2.12",
     "tailwindcss": "^4",
     "typescript": "^5"
   }