A11y: Fix code-pane focus order, focus visibility, tooltips, and View code button

[haoliuu]

Fixes for accessibility bugs against AI Dev Gallery. Each fix is in its own commit for independent review.

Fixes

• Code pane focus navigation (samples): Tab from the Code button now moves focus into the code pane (selected tab), and Shift+Tab from the pane returns focus to the Code button, instead of skipping far across the XAML tree.
• Focused link visibility (model page): Added bottom padding so the focus rectangle on the last documentation link is fully visible instead of being clipped by the card edge.
• Suggested sample tooltips (model page): Sample chips whose names are truncated now show a tooltip with the full name on hover/focus.
• Empty output focus (samples): Output scroll areas no longer take keyboard focus when empty, so Tab moves to the next interactive control. Applied consistently across 11 samples to match those already working correctly.
• View code button: Restyled the "View code" affordance with a bordered pill so it's clearly distinguishable from normal text.

Validation

Verified manually with keyboard navigation and Accessibility Insights for Windows on the reported page.

[Copilot]

Pull request overview

Accessibility-focused updates across the Scenario page, Model page, and multiple samples to improve keyboard navigation, focus visibility, and discoverability of UI affordances in AI Dev Gallery.

Changes:

• Updated sample output panes to avoid taking keyboard focus when they are non-interactive (ScrollViewer IsTabStop="False").
• Improved code-pane keyboard focus flow (Tab into code tabs; Shift+Tab back to the Code toggle) and focus visuals in the code viewer.
• Model page and card UI tweaks: padding fix to prevent clipped focus rectangles, added tooltips for sample chips, and restyled “View code” to read as a button.

Reviewed changes

Copilot reviewed 17 out of 17 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
AIDevGallery/Samples/WCRAPIs/TextToTable.xaml	Removes output scroll area from tab order.
AIDevGallery/Samples/WCRAPIs/TextSummarize.xaml	Removes output scroll area from tab order.
AIDevGallery/Samples/WCRAPIs/TextRewrite.xaml	Removes output scroll area from tab order.
AIDevGallery/Samples/WCRAPIs/PhiSilicaBasic.xaml	Removes output scroll area from tab order.
AIDevGallery/Samples/WCRAPIs/DescribeYourChange.xaml	Removes output scroll area from tab order.
AIDevGallery/Samples/Open Source Models/Language Models/Translate.xaml	Removes output scroll area from tab order.
AIDevGallery/Samples/Open Source Models/Language Models/SentimentAnalysis.xaml	Removes output scroll area from tab order.
AIDevGallery/Samples/Open Source Models/Language Models/Paraphrase.xaml	Removes output scroll area from tab order.
AIDevGallery/Samples/Open Source Models/Language Models/GrammarCheck.xaml	Removes output scroll area from tab order.
AIDevGallery/Samples/Open Source Models/Language Models/GenerateCode.xaml	Removes output scroll area from tab order.
AIDevGallery/Samples/Open Source Models/Language Models/ExplainCode.xaml	Removes output scroll area from tab order.
AIDevGallery/Pages/Scenarios/ScenarioPage.xaml.cs	Adds keyboard handling and focus return integration for the code pane.
AIDevGallery/Pages/Scenarios/ScenarioPage.xaml	Wires Code toggle PreviewKeyDown for Tab-to-code-pane behavior.
AIDevGallery/Pages/Models/ModelPage.xaml	Adds padding for focus visibility and tooltips for sample chips.
AIDevGallery/Controls/SampleContainer.xaml.cs	Adds focus-bridging helpers/events and code tab focus logic.
AIDevGallery/Controls/SampleContainer.xaml	Wires TabView PreviewKeyDown and enables system focus visuals for code border.
AIDevGallery/Controls/Card.xaml	Restyles “View code” into a more button-like pill while preserving the button behavior.