fix: reduce gunicorn workers to 2 for Railway memory limit

Procfile

@@ -1 +1 @@
-web: gunicorn main:app --preload --workers 28 --timeout 120
+web: gunicorn -w 2 -b 0.0.0.0:$PORT --timeout 120 main:app

railway.json

@@ -0,0 +1,12 @@
+{
+  "$schema": "https://railway.app/railway.schema.json",
+  "build": {
+    "builder": "DOCKERFILE",
+    "dockerfilePath": "Dockerfile"
+  },
+  "deploy": {
+    "startCommand": "cd /flask && gunicorn -w 2 -b 0.0.0.0:8000 --timeout 120 main:app",
+    "restartPolicyType": "ON_FAILURE",
+    "restartPolicyMaxRetries": 10
+  }
+}