fix: Handle date objects in JSON serialization for KRS audit

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

app.py

@@ -8783,18 +8783,20 @@ def api_krs_audit_trigger():
             audit.pkd_count = 1 if parsed_data.get('pkd_przewazajacy') else 0
             audit.pkd_count += len(parsed_data.get('pkd_pozostale', []))
 
-            # Convert Decimal values to float for JSON serialization
-            def decimal_to_float(obj):
+            # Convert non-JSON-serializable values for JSONB storage
+            def make_json_serializable(obj):
                 from decimal import Decimal
                 if isinstance(obj, Decimal):
                     return float(obj)
+                elif isinstance(obj, (datetime, date)):
+                    return obj.isoformat()
                 elif isinstance(obj, dict):
-                    return {k: decimal_to_float(v) for k, v in obj.items()}
+                    return {k: make_json_serializable(v) for k, v in obj.items()}
                 elif isinstance(obj, list):
-                    return [decimal_to_float(i) for i in obj]
+                    return [make_json_serializable(i) for i in obj]
                 return obj
 
-            audit.parsed_data = decimal_to_float(parsed_data)
+            audit.parsed_data = make_json_serializable(parsed_data)
             audit.pdf_downloaded_at = datetime.now()
 
             # Update company with parsed data