feat(DetailsView): Add CascadingTypeParameter for cleaner child syntax

DetailsView now cascades its ItemType to child components via
[CascadingTypeParameter], matching GridView's behavior. This allows:

Before:
  <BoundField ItemType="Course" DataField="Name" />

After:
  <BoundField DataField="Name" />

Updated skills documentation to reflect this cleaner pattern.

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

Author: csharpfritz

.github/skills/component-development/SKILL.md

@@ -50,13 +50,25 @@ Data controls that support BoundField, TemplateField, and other column types mus
 
 **How it works:**
 1. Parent component (GridView, DetailsView) implements `IColumnCollection<ItemType>`
-2. Parent provides cascading value: `<CascadingValue Value="this" Name="ColumnCollection">`
-3. Column components (BoundField, TemplateField) have `[CascadingParameter(Name = "ColumnCollection")]`
-4. On initialization, columns call `ParentColumnsCollection.AddColumn(this)` to register
+2. Parent uses `@attribute [CascadingTypeParameter(nameof(ItemType))]` to cascade the type to children
+3. Parent provides cascading value: `<CascadingValue Value="this" Name="ColumnCollection">`
+4. Column components (BoundField, TemplateField) have `[CascadingParameter(Name = "ColumnCollection")]`
+5. On initialization, columns call `ParentColumnsCollection.AddColumn(this)` to register
+6. Child components automatically receive the `ItemType` via Blazor's cascading type parameter — no need to specify `ItemType` on each child
 
 **Example:**
+```razor
+@* Parent component (.razor file) *@
+@typeparam ItemType
+@attribute [CascadingTypeParameter(nameof(ItemType))]
+
+<CascadingValue Value="this" Name="ColumnCollection">
+    @Fields
+</CascadingValue>
+```
+
 ```csharp
-// Parent component (DetailsView)
+// Parent component (.razor.cs file)
 public partial class DetailsView<ItemType> : IColumnCollection<ItemType>
 {
     private List<IColumn<ItemType>> _columnList = new();
@@ -65,11 +77,6 @@ public partial class DetailsView<ItemType> : IColumnCollection<ItemType>
     public void AddColumn(IColumn<ItemType> column) => _columnList.Add(column);
     public void RemoveColumn(IColumn<ItemType> column) => _columnList.Remove(column);
 }
-
-// In .razor file:
-<CascadingValue Value="this" Name="ColumnCollection">
-    @Fields
-</CascadingValue>
 ```
 
 ### Property Naming Convention

.github/skills/webforms-migration/SKILL.md

@@ -348,18 +348,18 @@ Data controls require additional changes for data binding:
     ItemType="Course"
     AutoGenerateRows="false">
     <Fields>
-        <BoundField ItemType="Course" DataField="CourseID" HeaderText="Course ID" />
-        <BoundField ItemType="Course" DataField="CourseName" HeaderText="Course Name" />
-        <BoundField ItemType="Course" DataField="StudentsMax" HeaderText="Max Students" />
+        <BoundField DataField="CourseID" HeaderText="Course ID" />
+        <BoundField DataField="CourseName" HeaderText="Course Name" />
+        <BoundField DataField="StudentsMax" HeaderText="Max Students" />
     </Fields>
 </DetailsView>
 ```
 
 **Key changes:**
 - `SelectMethod="GetCourse"` → `DataItem="_selectedCourse"` (bind to a field loaded in code)
 - `ItemType="Namespace.Class"` → `ItemType="Class"` (use short name, ensure `@using` directive exists)
-- BoundField needs `ItemType="Course"` attribute explicitly (required for column registration)
 - BoundField, TemplateField, and other column types work inside `<Fields>` just like Web Forms
+- Child components (BoundField, TemplateField) **inherit the type parameter** via Blazor's `[CascadingTypeParameter]` — no `ItemType` needed on each child
 
 #### Repeater
 

samples/AfterContosoUniversity/Pages/Courses.razor

@@ -44,9 +44,9 @@
             CssClass="details"
             AutoGenerateRows="false">
             <Fields>
-                <BoundField ItemType="Course" DataField="CourseID" HeaderText="Course ID" />
-                <BoundField ItemType="Course" DataField="CourseName" HeaderText="Course Name" />
-                <BoundField ItemType="Course" DataField="StudentsMax" HeaderText="Max Students" />
+                <BoundField DataField="CourseID" HeaderText="Course ID" />
+                <BoundField DataField="CourseName" HeaderText="Course Name" />
+                <BoundField DataField="StudentsMax" HeaderText="Max Students" />
             </Fields>
         </DetailsView>
     }

src/BlazorWebFormsComponents/DetailsView.razor

@@ -1,6 +1,7 @@
 @using BlazorWebFormsComponents.DataBinding
 @inherits DataBoundComponent<ItemType>
 @typeparam ItemType
+@attribute [CascadingTypeParameter(nameof(ItemType))]
 
 <CascadingValue Name="ParentDetailsView" Value="this" IsFixed="true">
 	@RowStyleContent