Tweaking the focus state for AP

[niels9001]

Adding the AI underline to the inputbox

[Copilot]

Pull Request Overview

This PR updates the AdvancedPaste PromptBox control's focus indicator by replacing theme-aware gradient border styling with a simpler gradient underline, and adjusts the loading text appearance.

• Replaces theme-specific gradient borders with a fixed gradient underline on the text input
• Simplifies the loading text styling by removing font weight and changing foreground color
• Removes ThemeDictionaries that provided different accent gradients for Default, Light, and HighContrast themes

[Copilot]

Use x:Key instead of x:Name for resource dictionary items. Resources defined in a ResourceDictionary should use x:Key to be referenced with {StaticResource}. Change to: <LinearGradientBrush x:Key="IntelligentUnderlineGradient" ...

Suggested change

	<LinearGradientBrush x:Name="IntelligentUnderlineGradient" StartPoint="0,0.5" EndPoint="1,0.5">
	<LinearGradientBrush x:Key="IntelligentUnderlineGradient" StartPoint="0,0.5" EndPoint="1,0.5">

[Copilot]

The hard-coded gradient colors do not adapt to different themes (Dark, Light, High Contrast). Consider wrapping this brush in ResourceDictionary.ThemeDictionaries with theme-specific color values to ensure proper contrast and accessibility across all themes, especially for High Contrast mode where this gradient may not be visible.

Suggested change

	<LinearGradientBrush x:Name="IntelligentUnderlineGradient" StartPoint="0,0.5" EndPoint="1,0.5">
	<GradientStop Offset="0.0" Color="#FF0078D4" />
	<GradientStop Offset="0.42" Color="#FF464FEB" />
	<GradientStop Offset="0.87" Color="#FFD660FF" />
	<GradientStop Offset="1.0" Color="#FFFEA874" />
	</LinearGradientBrush>
	<ResourceDictionary.ThemeDictionaries>
	<ResourceDictionary x:Key="Default">
	<LinearGradientBrush x:Key="IntelligentUnderlineGradient" StartPoint="0,0.5" EndPoint="1,0.5">
	<GradientStop Offset="0.0" Color="#FF0078D4" />
	<GradientStop Offset="0.42" Color="#FF464FEB" />
	<GradientStop Offset="0.87" Color="#FFD660FF" />
	<GradientStop Offset="1.0" Color="#FFFEA874" />
	</LinearGradientBrush>
	</ResourceDictionary>
	<ResourceDictionary x:Key="Light">
	<LinearGradientBrush x:Key="IntelligentUnderlineGradient" StartPoint="0,0.5" EndPoint="1,0.5">
	<GradientStop Offset="0.0" Color="#FF0078D4" />
	<GradientStop Offset="0.42" Color="#FF464FEB" />
	<GradientStop Offset="0.87" Color="#FFD660FF" />
	<GradientStop Offset="1.0" Color="#FFFEA874" />
	</LinearGradientBrush>
	</ResourceDictionary>
	<ResourceDictionary x:Key="Dark">
	<LinearGradientBrush x:Key="IntelligentUnderlineGradient" StartPoint="0,0.5" EndPoint="1,0.5">
	<GradientStop Offset="0.0" Color="#FF0078D4" />
	<GradientStop Offset="0.42" Color="#FF464FEB" />
	<GradientStop Offset="0.87" Color="#FFD660FF" />
	<GradientStop Offset="1.0" Color="#FFFEA874" />
	</LinearGradientBrush>
	</ResourceDictionary>
	<ResourceDictionary x:Key="HighContrast">
	<!-- Use system brush for visibility in High Contrast mode -->
	<SolidColorBrush x:Key="IntelligentUnderlineGradient" Color="{ThemeResource SystemColorHighlightColor}" />
	</ResourceDictionary>
	</ResourceDictionary.ThemeDictionaries>

[Copilot]

The removal of FontWeight="SemiBold" reduces the visual prominence of the loading text. Consider if this change is intentional, as loading states typically benefit from increased visual weight to draw user attention.

Suggested change

	Style="{StaticResource CaptionTextBlockStyle}"
	Style="{StaticResource CaptionTextBlockStyle}"
	FontWeight="SemiBold"