feat: migrate to Better Auth for authentication, update environment variables, and enhance database schema with accounts and sessions

Backend/package.json

@@ -8,7 +8,6 @@
     "@types/bun": "latest",
     "@types/cors": "^2.8.19",
     "@types/express": "^5.0.6",
-    "@types/jsonwebtoken": "^9.0.10",
     "@types/node": "^25.2.1",
     "@types/pg": "^8.16.0",
     "drizzle-kit": "^0.31.0",
@@ -26,7 +25,7 @@
     "drizzle-orm": "^0.44.0",
     "express": "^5.2.1",
     "helmet": "^8.1.0",
-    "jsonwebtoken": "^9.0.3",
+    "better-auth": "^1.4.0",
     "minio": "^8.0.6",
     "openai": "^6.18.0",
     "pg": "^8.18.0",
@@ -40,6 +39,7 @@
     "db:generate": "drizzle-kit generate",
     "db:migrate": "drizzle-kit migrate",
     "db:push": "drizzle-kit push",
-    "db:studio": "drizzle-kit studio"
+    "db:studio": "drizzle-kit studio",
+    "auth:migrate": "bun run scripts/migrate-better-auth.ts"
   }
 }