Version 1.0.1-Import, Validation, and Large-Sheet Performance

Added import structure confirmation for Excel and CSV files.
Imported data can now be rearranged to match the current table schema.
Unified live validation and Data Validation panel results.
Added automatic validation for int, float, bool, List, and Dictionary fields.
Improved onboarding guidance when live validation is disabled.
Refreshed product positioning and welcome-page content.
Improved scrolling, row/column operations, and refresh performance for large sheets.
Moved large JSON processing, exports, and extension loading to background tasks.
Improved formula compatibility and smart-quote handling.
Redesigned Trial upgrade guidance and version comparison.