chore: Upgrade OpenAI SDK from v5 to v6

Updated packages:
- openai: 5.23.2 → 6.0.1

Testing Results:
✅ TypeScript compilation: 0 errors
✅ Server running correctly
✅ All AI services loading successfully

🤖 Generated with Claude Code

maternal-app/maternal-app-backend/package-lock.json

@@ -45,7 +45,7 @@
         "langchain": "^0.3.35",
         "mailgun.js": "^12.1.0",
         "multer": "^2.0.2",
-        "openai": "^5.23.2",
+        "openai": "^6.0.1",
         "otplib": "^12.0.1",
         "passport": "^0.7.0",
         "passport-jwt": "^4.0.1",
@@ -12566,16 +12566,16 @@
       }
     },
     "node_modules/openai": {
-      "version": "5.23.2",
-      "resolved": "https://registry.npmjs.org/openai/-/openai-5.23.2.tgz",
-      "integrity": "sha512-MQBzmTulj+MM5O8SKEk/gL8a7s5mktS9zUtAkU257WjvobGc9nKcBuVwjyEEcb9SI8a8Y2G/mzn3vm9n1Jlleg==",
+      "version": "6.0.1",
+      "resolved": "https://registry.npmjs.org/openai/-/openai-6.0.1.tgz",
+      "integrity": "sha512-Xf9k3/Ezckp0aQmkU7LTXPg9dTxo3uspuJqxotHF3Jscq0r7EU0KEoqesQVxoQ6YeAzd/jlm7kxayZufpYRJUQ==",
       "license": "Apache-2.0",
       "bin": {
         "openai": "bin/cli"
       },
       "peerDependencies": {
         "ws": "^8.18.0",
-        "zod": "^3.23.8"
+        "zod": "^3.25 || ^4.0"
       },
       "peerDependenciesMeta": {
         "ws": {

maternal-app/maternal-app-backend/package.json

@@ -57,7 +57,7 @@
     "langchain": "^0.3.35",
     "mailgun.js": "^12.1.0",
     "multer": "^2.0.2",
-    "openai": "^5.23.2",
+    "openai": "^6.0.1",
     "otplib": "^12.0.1",
     "passport": "^0.7.0",
     "passport-jwt": "^4.0.1",