[Feature Request]: Audit follow-up: remaining Toolkit gaps and quality work #4364

Feature Title

Audit follow-up: remaining Toolkit gaps and quality work

Feature Description

Context: Standard WinForms coverage is effectively complete for everyday themed forms. What remains is quality work, optional new product, and a few housekeeping items. Items already shipped (KryptonToolTip, print preview, H/V scrollbars, ListView virtual mode, TreeView checkboxes, ComboBox Simple / DropDownList) are not listed here.

High — quality (not missing controls)

• Accessibility pass
  • Exercise Narrator (and optionally NVDA / JAWS) on KryptonMenuBar, KryptonTagInput, KryptonRating, KryptonListView virtual mode, Navigator caption-integrated tabs, and Ribbon RTL.
  • File follow-up bugs for anything that fails; do not treat this as a missing AutomationPeer layer (WinForms uses MSAA/UIA).
• DPI spot-check
  • Utilities extras and remaining owner-draw controls at 150% / 200% per-monitor DPI.
  • Per-monitor awareness stays an application manifest / ApplicationConfiguration concern; Krypton cannot force it for the host exe.
• Consumer mapping docs
  • Keep WinForms → Krypton mapping explicit, including Toolkit vs Krypton.Toolkit.Utilities (NuGet: Krypton.Standard.Toolkit) placement.
  • Stop documenting markdown editor/preview or KryptonSplitButton as shipped.

Smaller completeness nits

• KryptonListView themed header sort glyphs — ColumnClick and Sorting exist; confirm a visible sort indicator in themed details headers.
• RTL pass on Utilities extras — Ribbon RTL ([Bug/Feature Request]: RTL support for **all** Krypton.Ribbon controls #2382) is done; verify remaining Utilities controls.

Medium — optional new product

• Markdown editor / preview
  • There is no KryptonMarkdownEditor / KryptonMarkdownPreview. Closest: KryptonCodeEditor (Utilities) with Markdown highlighting, or HTML in KryptonWebView2.
  • Implement only if we want a first-class control; do not document as existing until then.
• Themed PageSetupDialog
  • KryptonIntegratedToolbarPageSetupCommand exists; there is no themed page-setup dialog.
• OS theme follow
  • Optional KryptonManager hook for Windows “Apps use light theme” and High Contrast.
  • Dark / light / high-contrast palettes already exist; apps must select them today.
• Charting
  • No KryptonChart. Prefer a documented third-party recommendation over a from-scratch chart unless product asks for one.

Low — housekeeping / API sugar

• KryptonToastNotificationManager
  • Toolkit Toolbox stub is empty. Toast UI is KryptonToast in Utilities. Flesh out the manager or remove/hide it so consumers are not pointed at a no-op.
• Remove obsolete KryptonScrollBar in V120 LTS
  • Already planned. Use KryptonHScrollBar / KryptonVScrollBar.
  • Cosmetic API over KryptonDropButton (Splitter defaults to true). Not required for WinForms parity.

Out of scope (do not implement / do not file as gaps)

• KryptonTabControl — use KryptonNavigator with NavigatorMode.BarTabGroup.
• Themed ImageList / BindingSource — non-visual; stock types work with Krypton.
• KryptonComboBox Simple inside KryptonDataGridView — an always-visible list cannot be hosted in a cell (by design, [Bug/Feature Request]: Add 'Simple' as a dropdown style for KryptonComboBox #4339).
• TreeView node-state persistence serializer — application-level, not a control feature.
• Raw Win11 IFileDialog chrome — Krypton file dialogs are themed wrappers by design.

Notes

• Core Toolkit toast/About/exception/search/code-editor consumer APIs for several of those features live in Utilities, not Krypton.Toolkit. Any new work should keep that split unless we explicitly move a type.
• Split this issue into child issues if a single item (markdown, charts, OS follow) becomes a real project.

Implementation Ideas (Optional)

No response