fix: normalize four-part updater versions for comparison

Co-authored-by: mamoreau-devolutions <242016029+mamoreau-devolutions@users.noreply.github.com>

Author: Copilot

src/UniGetUI.Core.Tools.Tests/ToolsTests.cs

@@ -140,6 +140,19 @@ public void TestGetVersionStringAsFloat(string version, int i1, int i2, int i3,
             Assert.Equal(i4, v.Remainder);
         }
 
+        [Theory]
+        [InlineData("2026.1.0", "2026.1.0")]
+        [InlineData("2026.1.0.0", "2026.1.0")]
+        [InlineData("2026.1.0.5", "2026.1.0")]
+        [InlineData("2026.1", "2026.1")]
+        public void TestNormalizeVersionForComparison(string rawVersion, string expected)
+        {
+            var version = System.Version.Parse(rawVersion);
+            var normalized = CoreTools.NormalizeVersionForComparison(version);
+
+            Assert.Equal(System.Version.Parse(expected), normalized);
+        }
+
         [Theory]
         [InlineData("Hello World", "Hello World")]
         [InlineData("Hello; World", "Hello World")]

src/UniGetUI.Core.Tools/Tools.cs

@@ -457,6 +457,13 @@ public static Version VersionStringToStruct(string Version)
             }
         }
 
+        public static System.Version NormalizeVersionForComparison(System.Version version)
+        {
+            return version.Revision >= 0
+                ? new System.Version(version.Major, version.Minor, version.Build)
+                : version;
+        }
+
         /// <summary>
         /// Returns the query that can be safely passed as a command-line parameter
         /// </summary>

src/UniGetUI/AutoUpdater.cs

@@ -745,13 +745,13 @@ private static Version ParseVersionOrFallback(string rawVersion, Version fallbac
     {
         if (Version.TryParse(rawVersion, out Version? parsed))
         {
-            return parsed;
+            return CoreTools.NormalizeVersionForComparison(parsed);
         }
 
         string sanitized = rawVersion.Trim().TrimStart('v', 'V');
         if (Version.TryParse(sanitized, out parsed))
         {
-            return parsed;
+            return CoreTools.NormalizeVersionForComparison(parsed);
         }
 
         Logger.Warn($"Could not parse version '{rawVersion}', using fallback '{fallbackVersion}'");