Refactor ensure_user_exists function to use maybe_single for user retrieval

app.py

@@ -76,7 +76,11 @@ def worker():
 # ————— Supabase Helpers —————
 def ensure_user_exists(chat_id: str):
     """Create user record if not exists."""
-    res = supabase.table("users").select("*").eq("chat_id", chat_id).single().execute()
+    res = supabase.table("users") \
+                    .select("*") \
+                    .eq("chat_id", chat_id) \
+                    .maybe_single() \
+                    .execute()
     if res.data is None:
         supabase.table("users").insert({
             "chat_id": chat_id,

requirements.txt

@@ -4,5 +4,4 @@ openai
 flask
 pillow
 requests
-supabase
-psycopg2
+supabase