fix(docs): resolve 20 broken links failing mkdocs build --strict

- Replace 9 broken cross-references in AjaxToolkit docs (Panel, ListBox,
  DropDownList, Image, RequiredFieldValidator) with plain text mentions
  since those doc pages don't exist yet
- Fix broken sample link in Migration/NET-Standard.md
- Replace 9 broken screenshot image links in migration test reports
  (runs 2, 3, 4) with text placeholders
- Fix invalid anchor #Migration---Getting-Started in Migration/readme.md

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: csharpfritz

docs/AjaxToolkit/AlwaysVisibleControlExtender.md

@@ -275,5 +275,5 @@ The AlwaysVisibleControlExtender requires **InteractiveServer** render mode:
 ## See Also
 
 - [Ajax Control Toolkit Overview](index.md) — How extenders work and render mode requirements
-- [Panel Component](../LayoutControls/Panel.md) — The Panel control
+- Panel Component — The Panel control (documentation coming soon)
 - Original Ajax Control Toolkit: https://www.asp.net/ajax/ajaxcontroltoolkit

docs/AjaxToolkit/DragPanelExtender.md

@@ -208,6 +208,6 @@ The DragPanelExtender requires **InteractiveServer** render mode:
 ## See Also
 
 - [Ajax Control Toolkit Overview](index.md) — How extenders work and render mode requirements
-- [Panel Component](../LayoutControls/Panel.md) — The Panel control
+- Panel Component — The Panel control (documentation coming soon)
 - [ResizableControlExtender](ResizableControlExtender.md) — Make panels resizable
 - Original Ajax Control Toolkit: https://www.asp.net/ajax/ajaxcontroltoolkit

docs/AjaxToolkit/DropShadowExtender.md

@@ -244,6 +244,6 @@ The DropShadowExtender requires **InteractiveServer** render mode:
 ## See Also
 
 - [Ajax Control Toolkit Overview](index.md) — How extenders work and render mode requirements
-- [Panel Component](../LayoutControls/Panel.md) — The Panel control
+- Panel Component — The Panel control (documentation coming soon)
 - [RoundedCornersExtender](RoundedCornersExtender.md) — Apply rounded corners to elements
 - Original Ajax Control Toolkit: https://www.asp.net/ajax/ajaxcontroltoolkit

docs/AjaxToolkit/ListSearchExtender.md

@@ -313,6 +313,6 @@ The ListSearchExtender requires **InteractiveServer** render mode:
 ## See Also
 
 - [Ajax Control Toolkit Overview](index.md) — How extenders work and render mode requirements
-- [ListBox Component](../DataControls/ListBox.md) — The ListBox control
-- [DropDownList Component](../DataControls/DropDownList.md) — The DropDownList control
+- ListBox Component — The ListBox control (documentation coming soon)
+- DropDownList Component — The DropDownList control (documentation coming soon)
 - Original Ajax Control Toolkit: https://www.asp.net/ajax/ajaxcontroltoolkit

docs/AjaxToolkit/ResizableControlExtender.md

@@ -265,6 +265,6 @@ The ResizableControlExtender requires **InteractiveServer** render mode:
 ## See Also
 
 - [Ajax Control Toolkit Overview](index.md) — How extenders work and render mode requirements
-- [Panel Component](../LayoutControls/Panel.md) — The Panel control
+- Panel Component — The Panel control (documentation coming soon)
 - [DragPanelExtender](DragPanelExtender.md) — Make panels draggable
 - Original Ajax Control Toolkit: https://www.asp.net/ajax/ajaxcontroltoolkit

docs/AjaxToolkit/RoundedCornersExtender.md

@@ -261,6 +261,6 @@ Use the RoundedCornersExtender primarily for dynamic scenarios or legacy compone
 ## See Also
 
 - [Ajax Control Toolkit Overview](index.md) — How extenders work and render mode requirements
-- [Panel Component](../LayoutControls/Panel.md) — The Panel control
+- Panel Component — The Panel control (documentation coming soon)
 - [DropShadowExtender](DropShadowExtender.md) — Add drop shadows to elements
 - Original Ajax Control Toolkit: https://www.asp.net/ajax/ajaxcontroltoolkit

docs/AjaxToolkit/SlideShowExtender.md

@@ -332,5 +332,5 @@ The SlideShowExtender requires **InteractiveServer** render mode:
 ## See Also
 
 - [Ajax Control Toolkit Overview](index.md) — How extenders work and render mode requirements
-- [Image Component](../WebControls/Image.md) — The Image control
+- Image Component — The Image control (documentation coming soon)
 - Original Ajax Control Toolkit: https://www.asp.net/ajax/ajaxcontroltoolkit

docs/AjaxToolkit/UpdatePanelAnimationExtender.md

@@ -312,5 +312,5 @@ The UpdatePanelAnimationExtender requires **InteractiveServer** render mode:
 ## See Also
 
 - [Ajax Control Toolkit Overview](index.md) — How extenders work and render mode requirements
-- [Panel Component](../LayoutControls/Panel.md) — The Panel control
+- Panel Component — The Panel control (documentation coming soon)
 - Original Ajax Control Toolkit: https://www.asp.net/ajax/ajaxcontroltoolkit

docs/AjaxToolkit/ValidatorCalloutExtender.md

@@ -342,6 +342,6 @@ The ValidatorCalloutExtender requires **InteractiveServer** render mode:
 
 - [Ajax Control Toolkit Overview](index.md) — How extenders work and render mode requirements
 - [TextBox Component](../EditorControls/TextBox.md) — The TextBox control
-- [RequiredFieldValidator](../Validators/RequiredFieldValidator.md) — Validator control
+- RequiredFieldValidator — Validator control (documentation coming soon)
 - [PasswordStrength](PasswordStrength.md) — Password feedback extender
 - Original Ajax Control Toolkit: https://www.asp.net/ajax/ajaxcontroltoolkit

docs/Migration/NET-Standard.md

@@ -21,7 +21,7 @@ Portability is not guaranteed when you migrate business logic to .NET Standard.
 
 ## Sample 1: Update an existing class library
 
-The first sample demonstrates updating a simple class library to .NET Standard.  In this model, we're assuming that you already have your business logic code properly separated from your user-interface and managed inside a class-library project that targets .NET Framework 4.5.  You can find it in [samples/netstandard-1](../samples/netstandard-1/README.md) folder.
+The first sample demonstrates updating a simple class library to .NET Standard.  In this model, we're assuming that you already have your business logic code properly separated from your user-interface and managed inside a class-library project that targets .NET Framework 4.5.  You can find it in the `samples/netstandard-1` folder in the repository.
 
 ## Sample 2: Refactoring Business Logic