Update app.py

app.py

@@ -1675,7 +1675,7 @@ def stitch_story(raw_story: List[dict], theme_id: str, level: str) -> Dict[str,
         
         # Generate polished English version
         response = client.chat.completions.create(
-            model="gpt-4",
+            model="gpt-4o-mini",
             messages=[
                 {
                     "role": "system",
@@ -1705,7 +1705,7 @@ def stitch_story(raw_story: List[dict], theme_id: str, level: str) -> Dict[str,
         
         # Generate Thai translation
         translation_response = client.chat.completions.create(
-            model="gpt-4",
+            model="gpt-4o-mini",
             messages=[
                 {
                     "role": "system",
@@ -3134,7 +3134,7 @@ def generate_stitched_story(story: List[dict], style: str, detail_level: str, th
         
         # Generate polished version
         response = client.chat.completions.create(
-            model="gpt-4",
+            model="gpt-4o-mini",
             messages=[
                 {
                     "role": "system",
@@ -3170,7 +3170,7 @@ def generate_stitched_story(story: List[dict], style: str, detail_level: str, th
         
         # Generate Thai translation with matching style
         translation_response = client.chat.completions.create(
-            model="gpt-4",
+            model="gpt-4o-mini",
             messages=[
                 {
                     "role": "system",