Update app/mapper.py

app/mapper.py

@@ -45,7 +45,7 @@ def ensure_canonical_table(duck: duckdb.DuckDBPyConnection, df: pd.DataFrame) ->
     """)
     
     # Get existing columns (lowercase for comparison)
-    existing_cols = {r[0].lower() for r in duck.execute(f"PRAGMA table_info('{table_name}')").fetchall()}
+    existing_cols_raw = duck.execute(f"PRAGMA table_info('{table_name}')").fetchall()existing_cols = {str(r[0]).lower() for r in existing_cols_raw}  # ✅ FORCE STRING
     
     # ✅ BULLETPROOF: Add missing columns with safe name handling
     for col in df.columns:
@@ -210,7 +210,7 @@ def canonify_df(org_id: str, hours_window: int = 24) -> tuple[pd.DataFrame, str,
     if not df.empty:
         # Get current table columns
         table_info = duck.execute(f"PRAGMA table_info('{table_name}')").fetchall()
-        table_cols = [r[0] for r in table_info]
+        table_cols = [str(r[0]) for r in table_info]  # ✅ FORCE STRING
         
         # Only insert columns that exist in table
         df_to_insert = df[[col for col in df.columns if col in table_cols]]