Refactors UI components with new card header structure

Replaces `swp-section-label` with standardized `swp-card-header` and `swp-card-title`

Improves component consistency across multiple features:
- Adds structured card headers
- Introduces more semantic HTML elements
- Enhances layout and readability of card components

Updates CSS and component styles to support new structure

PlanTempus.Application/Features/Dashboard/Components/QuickStatList/Default.cshtml

@@ -1,7 +1,9 @@
 @model PlanTempus.Application.Features.Dashboard.Components.QuickStatListViewModel
 
 <swp-card data-key="@Model.Key">
-    <swp-section-label>@Model.Title</swp-section-label>
+    <swp-card-header>
+        <swp-card-title>@Model.Title</swp-card-title>
+    </swp-card-header>
     <swp-card-content>
         <swp-quick-stats>
             @foreach (var statKey in Model.StatKeys)