fix(a11y): add visible keyboard focus ring and toggle semantics to QueryaIconButton #1370

Summary

In Querya UI Kit QueryaIconButton and QueryaToolbarButton (lib/shared/widgets/querya_icon_button.dart, lines 97–132, 147–170):

QueryaIconButton is used across toolbars, header chrome, and data grid bars. It currently has two major accessibility (a11y) shortcomings:

1. No visible focus indicator: The underlying material.InkWell handles keyboard focus, but no focus ring or border outline (colors.ring / 2px border) is drawn. Keyboard users navigating via Tab / Shift+Tab cannot see where focus is located.
2. Missing toggle semantics: Many toolbar icon buttons represent toggles (isActive = true/false, e.g., Word Wrap, Line Numbers, Filter, PII Masking). However, the button does not declare Semantics(toggled: isActive) or Semantics(selected: isActive). Screen readers announce them only as generic buttons without state.

Scope & Implementation

• Track focus state (or supply focusColor and a 2px cs.ring border when focused) in QueryaIconButton.
• Wrap the button in material.Semantics:
  • button: true
  • enabled: onPressed != null
  • toggled: isActive
  • label: tooltip
• Connect with Epic epic(ui): buttons in the Querya UI kit: one control scale, our own button family, no shadcn buttons #1331 (Button family standardization in Querya UI Kit).