Changes sessions to be stored in the DB, this ensures that sessions persist after a restart!

prisma/schema.prisma

@@ -121,3 +121,11 @@ model ChatMessage {
   createdAt DateTime   @default(now()) @map("created_at")
   thread    ChatThread @relation(fields: [threadId], references: [id], onDelete: Cascade)
 }
+
+// Add this model for session storage
+model Session {
+  id        String   @id
+  sid       String   @unique
+  data      String
+  expiresAt DateTime @map("expires_at")
+}