chore: snapshot workflow migration progress

backend/app/services/chat_service.py

@@ -13,6 +13,7 @@ from sqlalchemy import text
 from sqlalchemy.ext.asyncio import AsyncSession
 
 from app.config import settings
+from app.core.render_paths import result_path_to_public_url
 
 logger = logging.getLogger(__name__)
 
@@ -774,12 +775,7 @@ async def _tool_find_product_renders(
     renders = []
     for r in rows:
         path = r["result_path"] or ""
-        # Convert internal path to servable URL
-        url = None
-        if "/renders/" in path:
-            url = path[path.index("/renders/"):]
-        elif "/thumbnails/" in path:
-            url = path[path.index("/thumbnails/"):]
+        url = result_path_to_public_url(path, require_exists=True)
 
         # Effective material override (line overrides output type)
         material = r["line_material_override"] or r["ot_material_override"] or None