Bugfix plate selection settings refresh

[shixiaozhong]

Description

Fix stale plate settings when switching plates through the thumbnail selector.

Previously, the corresponding plate was highlighted in the object list, but the settings panel could still display the previous plate's values. The list selection event handler returns early when the mouse is outside the list.

This change explicitly calls part_selection_changed() after programmatically selecting a different plate node, keeping the settings panel synchronized with the selection.

No breaking changes or dependency changes.

Screenshots/Recordings/Graphs

Tests

• Passed git diff --check.
• Reviewed the plate selection and settings refresh call paths.
• Manual UI verification is pending:
  • Switch between plate thumbnails with different print sequence or skirt start point settings.
  • Edit a setting after switching and confirm only the selected plate is affected.
  • Verify object-list selection, deselection, and automatic plate switching during Slice All.

[lzqiang46-cyber]

look nice to me