Fixed database column names (create_time/modified_time instead of create_date/modified_date)<br />Fixed content storage - article content and summaries now correctly stored in fieldval table<br />Added automatic creation of Content and Summary field definitions<br />Fixed field definition inserts to use correct LISE schema (name, alias, help, type, position, required, template, extra)<br />Removed duplicate statistics display in migration interface<br />Added visible labels for radio buttons in instance selection<br />Split MigrationEngine.php into smaller modules to comply with 500 line limit<br />Added Start Migration button to preview section<br />Fixed callback error for logging functionality