Implement natural string sorting for software versions

Marechai.App/Presentation/ViewModels/SoftwareViewViewModel.cs

@@ -9,6 +9,7 @@ using System.Threading.Tasks;
 using System.Windows.Input;
 using Marechai.ApiClient.Models;
 using Marechai.App.Navigation;
+using Marechai.Data;
 using Marechai.App.Presentation.Views;
 using Marechai.App.Services;
 using Marechai.App.Services.Caching;
@@ -182,6 +183,7 @@ public partial class SoftwareViewViewModel : ObservableObject, IRegionAware
 
             // Load versions (without nested releases)
             List<SoftwareVersionDto> versions = await _browsingService.GetVersionsAsync(softwareId);
+            versions.Sort((a, b) => NaturalStringComparer.Instance.Compare(a.VersionString, b.VersionString));
 
             foreach(SoftwareVersionDto version in versions)
             {

Marechai.Data/NaturalStringComparer.cs

@@ -0,0 +1,75 @@
+using System;
+using System.Collections.Generic;
+
+namespace Marechai.Data;
+
+/// <summary>
+///     Compares strings using natural sort order, where numeric segments are compared by value rather than
+///     lexicographically. For example, "4.00.96" sorts before "4.00.111".
+/// </summary>
+public sealed class NaturalStringComparer : IComparer<string>
+{
+    public static readonly NaturalStringComparer Instance = new();
+
+    public int Compare(string x, string y)
+    {
+        if(ReferenceEquals(x, y)) return 0;
+        if(x is null) return -1;
+        if(y is null) return 1;
+
+        int ix = 0, iy = 0;
+
+        while(ix < x.Length && iy < y.Length)
+        {
+            bool xIsDigit = char.IsDigit(x[ix]);
+            bool yIsDigit = char.IsDigit(y[iy]);
+
+            if(xIsDigit && yIsDigit)
+            {
+                // Skip leading zeros and compare numeric segments by value
+                int xStart = ix;
+                int yStart = iy;
+
+                while(ix < x.Length && x[ix] == '0') ix++;
+                while(iy < y.Length && y[iy] == '0') iy++;
+
+                int xNumStart = ix;
+                int yNumStart = iy;
+
+                while(ix < x.Length && char.IsDigit(x[ix])) ix++;
+                while(iy < y.Length && char.IsDigit(y[iy])) iy++;
+
+                int xLen = ix - xNumStart;
+                int yLen = iy - yNumStart;
+
+                // Longer numeric segment is larger
+                if(xLen != yLen) return xLen.CompareTo(yLen);
+
+                // Same length: compare digit by digit
+                for(int i = 0; i < xLen; i++)
+                {
+                    int cmp = x[xNumStart + i].CompareTo(y[yNumStart + i]);
+
+                    if(cmp != 0) return cmp;
+                }
+
+                // Values equal — more leading zeros means smaller (e.g., "007" < "7" is debatable, keep stable)
+                int xLeadingZeros = xNumStart - xStart;
+                int yLeadingZeros = yNumStart - yStart;
+
+                if(xLeadingZeros != yLeadingZeros) return xLeadingZeros.CompareTo(yLeadingZeros);
+            }
+            else
+            {
+                int cmp = char.ToUpperInvariant(x[ix]).CompareTo(char.ToUpperInvariant(y[iy]));
+
+                if(cmp != 0) return cmp;
+
+                ix++;
+                iy++;
+            }
+        }
+
+        return x.Length.CompareTo(y.Length);
+    }
+}

Marechai/Pages/Software/View.razor.cs

@@ -28,6 +28,7 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
 using Marechai.ApiClient.Models;
+using Marechai.Data;
 using Microsoft.AspNetCore.Components;
 
 namespace Marechai.Pages.Software;
@@ -80,6 +81,7 @@ public partial class View
 
         _companies = await Service.GetCompaniesAsync(Id);
         _versions  = await Service.GetVersionsAsync(Id);
+        _versions.Sort((a, b) => NaturalStringComparer.Instance.Compare(a.VersionString, b.VersionString));
 
         // Load all non-compilation releases for this software (flat list)
         _releases = await Service.GetReleasesBySoftwareAsync(Id);