[ZhuchkaTriplesix]

Closes #1431

Changes

1. Suppress debounce timers during programmatic text updates:
   • Added _isProgrammaticUpdate flag and helper _setControllerTextProgrammatically.
   • In didUpdateWidget, setting cellValue updates the controller without triggering the 150 ms debounce timer.
   • Synchronous validation runs once without being followed 150 ms later by a duplicate validation callback.
2. Handle Format / Minify cleanly:
   • _formatCode() and _minifyCode() now use _setControllerTextProgrammatically and invoke validation immediately rather than waiting on an unnecessary debounce delay.
3. Unit tests:
   • Added test in test/features/workspace/data_grid_value_panel_test.dart verifying immediate synchronous validation on didUpdateWidget and absence of scheduled timers.