Complete preferences and chooser help coverage

Add Help/F1 support to Preferences, Render Log, Blender Add-on Reset, and the piece and custom color choosers. Share help routing between dialogs and menu-embedded widgets while preserving chooser selections and shortcut recording.

Explain all Preferences controls, link labels to their fields, and correct the Color Theme label buddy. Make Blender reset cancellation preserve pending edits and retain Apply availability after an accepted reset. Refresh catalogs while keeping existing translations and new strings unfinished.

Validation: debug build, all seven Preferences tabs, 85 field F1 routes, label buddies, F1 shortcut recording, native chooser menu Help/Escape, reset Cancel/Apply behavior, layouts, and catalog preservation checks passed.

docs/dialog-help.md

@@ -22,7 +22,10 @@ Add the standard Help button to the dialog's button box, then call
 `lcSetupDialogHelp()` after `setupUi()`. Help shows the dialog overview. F1 shows
 help for the focused control, falling back through its parent groups to the
 dialog overview. This also handles focus inside composite controls such as
-spin boxes. Both entry points use Qt's native What's This popup.
+spin boxes. Both entry points use Qt's native What's This popup. For QWidget-based choosers
+embedded in menus, use `lcSetupWidgetHelp()` and verify that help does not accept
+a choice or close the menu. Shortcut-recording fields may capture F1 as input;
+keep the Help button available for those fields.
 
 Give unlabeled controls meaningful accessible names. Check Help, F1, and Escape
 with keyboard navigation, as well as tooltip placement and longer translated