refactor: overhaul armature validation system to be opt-in by default

- Change default validation mode from STRICT to NONE (disabled)
- Move validation from automatic panel draw to explicit "Validate Now" button
- Hide validation results when mode is changed to NONE
- Fix PMX/MMD model detection to check mmd_type value, not just attribute existence
- Add new validation result collapsible sections
- Improve UI presentation with better visual hierarchy
- Add translation strings for new validation UI elements

core/updater.py

@@ -20,7 +20,7 @@ GITHUB_REPO = "teamneoneko/Avatar-Toolkit"
 # Define which version series this installation can update to
 # For example: ["0.1"] means only look for 0.1.x updates
 # ["0.2", "0.3"] would look for both 0.2.x and 0.3.x
-ALLOWED_ = ["0.5"]
+ALLOWED_ = ["0.6"]
 
 is_checking_for_update: bool = False
 update_needed: bool = False