Align Toolbar with M3 Bottom App Bar specs (80dp height, vertical centering)

Co-authored-by: haavamoa <2527084+haavamoa@users.noreply.github.com>

Author: Copilot

src/library/DIPS.Mobile.UI/Components/Toolbar/Android/ToolbarHandler.cs

@@ -29,12 +29,13 @@ protected override LinearLayout CreatePlatformView()
         border.SetBackgroundColor(Resources.Colors.Colors.GetColor(ColorName.color_border_default).ToPlatform());
         outer.AddView(border, new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MatchParent, borderPx));
 
-        // Buttons row
+        // Buttons row: fills remaining space, centers buttons vertically (M3 spec: icons vertically centered in 80dp bar)
         m_buttonsLayout = new LinearLayout(Context)
         {
             Orientation = Orientation.Horizontal,
+            Gravity = GravityFlags.CenterVertical,
         };
-        outer.AddView(m_buttonsLayout, new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MatchParent, ViewGroup.LayoutParams.WrapContent));
+        outer.AddView(m_buttonsLayout, new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MatchParent, ViewGroup.LayoutParams.MatchParent));
 
         return outer;
     }

src/library/DIPS.Mobile.UI/Components/Toolbar/Toolbar.cs

@@ -5,11 +5,22 @@ namespace DIPS.Mobile.UI.Components.Toolbar;
 /// </summary>
 /// <remarks>
 /// iOS: https://developer.apple.com/design/human-interface-guidelines/toolbars
-/// Android: https://m3.material.io/components/toolbars/overview
+/// Android: https://m3.material.io/components/toolbars/overview (Bottom App Bar, height 80dp)
 /// </remarks>
 [ContentProperty(nameof(Buttons))]
 public partial class Toolbar : View
 {
+    public Toolbar()
+    {
+        // M3 Bottom App Bar spec: height = 80dp
+        HeightRequest = Sizes.GetSize(SizeName.size_20);
+    }
+
+    private void OnButtonsChanged()
+    {
+        Handler?.UpdateValue(nameof(Buttons));
+    }
+
     protected override void OnBindingContextChanged()
     {
         base.OnBindingContextChanged();