feat(ui): add UpdateCheckService

src/ClaudeDo.Ui/ClaudeDo.Ui.csproj

@@ -2,6 +2,7 @@
 
   <ItemGroup>
     <ProjectReference Include="..\ClaudeDo.Data\ClaudeDo.Data.csproj" />
+    <ProjectReference Include="..\ClaudeDo.Releases\ClaudeDo.Releases.csproj" />
   </ItemGroup>
 
   <ItemGroup>

src/ClaudeDo.Ui/Services/UpdateCheckService.cs

@@ -0,0 +1,73 @@
+using ClaudeDo.Releases;
+using CommunityToolkit.Mvvm.ComponentModel;
+
+namespace ClaudeDo.Ui.Services;
+
+public enum UpdateCheckStatus
+{
+    NeverChecked,
+    CheckFailed,
+    UpToDate,
+    UpdateAvailable,
+}
+
+public sealed partial class UpdateCheckService : ObservableObject
+{
+    private readonly IReleaseClient _releases;
+
+    [ObservableProperty] private bool _isUpdateAvailable;
+    [ObservableProperty] private string? _latestVersion;
+    [ObservableProperty] private string _currentVersion;
+    [ObservableProperty] private bool _isChecking;
+    [ObservableProperty] private UpdateCheckStatus _lastCheckStatus = UpdateCheckStatus.NeverChecked;
+
+    public UpdateCheckService(IReleaseClient releases, string currentVersion)
+    {
+        _releases = releases;
+        _currentVersion = currentVersion;
+    }
+
+    public async Task CheckNowAsync(CancellationToken ct)
+    {
+        IsChecking = true;
+        try
+        {
+            GiteaRelease? rel;
+            try
+            {
+                rel = await _releases.GetLatestReleaseAsync(ct);
+            }
+            catch
+            {
+                LastCheckStatus = UpdateCheckStatus.CheckFailed;
+                IsUpdateAvailable = false;
+                return;
+            }
+
+            if (rel is null)
+            {
+                LastCheckStatus = UpdateCheckStatus.CheckFailed;
+                IsUpdateAvailable = false;
+                return;
+            }
+
+            var latest = (rel.TagName ?? "").TrimStart('v', 'V');
+            var cmp = VersionComparer.Compare(latest, CurrentVersion);
+            if (cmp.IsNewer)
+            {
+                LatestVersion = latest;
+                IsUpdateAvailable = true;
+                LastCheckStatus = UpdateCheckStatus.UpdateAvailable;
+            }
+            else
+            {
+                IsUpdateAvailable = false;
+                LastCheckStatus = UpdateCheckStatus.UpToDate;
+            }
+        }
+        finally
+        {
+            IsChecking = false;
+        }
+    }
+}