chore: downgrade Prisma to v6.19.3, remove redundant config files, and update schema datasource configurations

package.json

@@ -19,9 +19,9 @@
   },
   "dependencies": {
     "@google/genai": "^1.30.0",
-    "@prisma/adapter-pg": "^7.6.0",
-    "@prisma/client": "^7.7.0",
-    "@prisma/config": "^7.6.0",
+    "@prisma/adapter-pg": "6.19.3",
+    "@prisma/client": "6.19.3",
+    "@prisma/config": "6.19.3",
     "@tailwindcss/postcss": "^4.2.2",
     "@tailwindcss/typography": "^0.5.19",
     "@types/bcryptjs": "^2.4.6",
@@ -30,11 +30,12 @@
     "autoprefixer": "^10.4.27",
     "bcryptjs": "^3.0.3",
     "dotenv": "^17.3.1",
+    "jiti": "^2.6.1",
     "lucide-react": "^0.554.0",
     "next": "^16.1.6",
     "pg": "^8.19.0",
     "postcss": "^8.5.10",
-    "prisma": "^7.7.0",
+    "prisma": "6.19.3",
     "react": "^19.2.0",
     "react-dom": "^19.2.0",
     "react-hot-toast": "^2.6.0",