Fix incorrect panel height calculation in complex layout

src/Spectre.Console/Internal/Ratio.cs

@@ -9,7 +9,17 @@ public static List<int> Resolve(int total, IEnumerable<IRatioResolvable> edges)
     {
         static (int Div, float Mod) DivMod(float x, float y)
         {
-            return ((int)(x / y), x % y);
+            var (div, mod) = ((int)(x / y), x % y);
+
+            // If remainder is withing .0001 of 1 then we round up
+            if (!(mod > 0.9999))
+            {
+                return (div, mod);
+            }
+
+            div++;
+            mod = 0;
+            return (div, mod);
         }
 
         static int? GetEdgeWidth(IRatioResolvable edge)
@@ -22,7 +32,7 @@ public static List<int> Resolve(int total, IEnumerable<IRatioResolvable> edges)
             return edge.Size;
         }
 
-        var sizes = edges.Select(x => GetEdgeWidth(x)).ToArray();
+        var sizes = edges.Select(GetEdgeWidth).ToArray();
 
         while (sizes.Any(s => s == null))
         {

src/Tests/Spectre.Console.Tests/Expectations/Widgets/Layout/Render_Layout_With_Three_And_One_Columns.Output.verified.txt

@@ -0,0 +1,17 @@
+┌──────────────────┐┌──────────────────┐
+│ Hello, World!    ││ Hello, World!    │
+│                  ││                  │
+│                  ││                  │
+└──────────────────┘│                  │
+┌──────────────────┐│                  │
+│ Hello, World!    ││                  │
+│                  ││                  │
+│                  ││                  │
+│                  ││                  │
+└──────────────────┘│                  │
+┌──────────────────┐│                  │
+│ Hello, World!    ││                  │
+│                  ││                  │
+│                  ││                  │
+│                  ││                  │
+└──────────────────┘└──────────────────┘

src/Tests/Spectre.Console.Tests/Unit/Widgets/LayoutTests.cs

@@ -264,4 +264,37 @@ public Task Should_Fall_Back_To_Parent_Layout_If_All_Children_Are_Invisible()
         // Then
         return Verifier.Verify(console.Output);
     }
+
+    [Fact]
+    [Expectation("Render_Layout_With_Three_And_One_Columns")]
+    public Task Should_Render_Layout_With_Three_And_One_Columns()
+    {
+        // Given
+        var console = new TestConsole().Size(new Size(40, 17));
+        var layout = new Layout();
+        var col1 = new Layout();
+        var col1Row1 = new Layout();
+        var col1Row2 = new Layout();
+        var col1Row3 = new Layout();
+
+        col1.SplitRows(col1Row1, col1Row2, col1Row3);
+
+        var col2 = new Layout();
+
+        layout.SplitColumns(col1, col2);
+
+        var panel = new Panel("Hello, World!") { Expand = true };
+
+        List<Layout> layouts = [col1Row1, col1Row2, col1Row3, col2];
+        foreach (var l in layouts)
+        {
+            l.Update(panel);
+        }
+
+        // When
+        console.Write(layout);
+
+        // Then
+        return Verifier.Verify(console.Output);
+    }
 }