The import wizard now proactively checks the `MAX_CATEGORIES` limit during
the proposal and configuration steps.
Advancing is blocked with a descriptive message if the limit would be
exceeded.
Fixed UI rendering order in `ImportWizardWidget` so messages are correctly
displayed.
Add regression tests for category limit enforcement.
Co-Authored-By: fiddlerwoaroof/git-smart-commit (unsloth/gemma-4-26B-A4B-it-GGUF:UD-Q5_K_XL)
Edward Langley
77a5124d16