Add carousel navigation and the mixed checkbox state, without script

These were left out because daisyUI does them with scripts or with links that
<base href="/"> breaks.

DCarousel:
- ShowNavigation adds previous/next links on each slide, and ShowIndicators adds
  a row of numbered links under the strip.
- The links point at the slides' ids under the current path, so Blazor treats
  them as same-page fragments and scrolls the strip.

DCheckbox:
- Indeterminate renders aria-checked="mixed", which daisyUI draws like
  :indeterminate.
- A click clears it through IndeterminateChanged.
- The neo inset well leaves the mixed state alone.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LsXgEaXee4GCU1hwYgPJXw

Components/Daisy/DataDisplay/DCarousel.razor

@@ -1,15 +1,45 @@
 @inherits DComponentBase
+@inject NavigationManager NavigationManager
 
 @* daisyUI Carousel: https://daisyui.com/components/carousel/ . A scroll-snap strip of DCarouselItem children; the
-   user scrolls or swipes it. Give each item w-full for one slide at a time. *@
-<div @attributes="AdditionalAttributes" class="@CssClass">
-	@ChildContent
-</div>
+   user scrolls or swipes it. Give each item w-full for one slide at a time. ShowNavigation (previous/next on every
+   slide) and ShowIndicators (numbered buttons under the strip) are links to the slides' ids, as in daisyUI's examples:
+   they keep the current path, so Blazor treats them as same-page fragments and scrolls the slide into view. *@
+<CascadingValue Value="this" IsFixed="true">
+	@if (ShowIndicators)
+	{
+		<div class="flex flex-col gap-2">
+			@Strip
+			<div class="flex w-full justify-center gap-2">
+				@for (var i = 0; i < items.Count; i++)
+				{
+					<a href="@Link(i)" class="btn btn-xs" aria-label="@($"{SlideText} {i + 1}")">@(i + 1)</a>
+				}
+			</div>
+		</div>
+	}
+	else
+	{
+		@Strip
+	}
+</CascadingValue>
 
 @code {
 	[Parameter] public RenderFragment ChildContent { get; set; }
 	[Parameter] public DCarouselSnap Snap { get; set; }
 	[Parameter] public DDirection Direction { get; set; }
+	/// <summary>Previous/next buttons on every slide.</summary>
+	[Parameter] public bool ShowNavigation { get; set; }
+	/// <summary>A row of numbered buttons under the strip, one per slide.</summary>
+	[Parameter] public bool ShowIndicators { get; set; }
+	[Parameter] public string PreviousText { get; set; } = "Previous slide";
+	[Parameter] public string NextText { get; set; } = "Next slide";
+	[Parameter] public string SlideText { get; set; } = "Slide";
+
+	readonly List<DCarouselItem> items = new();
+	readonly string uid = "d" + Guid.NewGuid().ToString("N")[..8];
+
+	RenderFragment Strip => @<div @attributes="AdditionalAttributes" class="@CssClass">@ChildContent</div>;
 
 	string CssClass => Cx("carousel", SnapClass, Direction == DDirection.Vertical ? "carousel-vertical" : null, Class);
 
@@ -19,4 +49,32 @@
 		DCarouselSnap.End => "carousel-end",
 		_ => null
 	};
+
+	internal int Count => items.Count;
+
+	internal int IndexOf(DCarouselItem item) => items.IndexOf(item);
+
+	internal string SlideId(int index) => $"{uid}-{index + 1}";
+
+	/// <summary>The current page plus the slide's fragment; the index wraps around.</summary>
+	internal string Link(int index)
+	{
+		var path = NavigationManager.ToBaseRelativePath(NavigationManager.Uri);
+		var hash = path.IndexOf('#');
+		if (hash >= 0)
+			path = path[..hash];
+		return $"{path}#{SlideId((index % items.Count + items.Count) % items.Count)}";
+	}
+
+	internal void Add(DCarouselItem item)
+	{
+		items.Add(item);
+		StateHasChanged();
+	}
+
+	internal void Remove(DCarouselItem item)
+	{
+		items.Remove(item);
+		StateHasChanged();
+	}
 }