Add Update Checker

Commands/ScanCommand.cs

@@ -28,12 +28,17 @@ public class ScanCommand : AsyncCommand<ModPathSettings>
             var gitHubApiService = new GitHubApiService();
             var modDiscoveryService = new ModDiscoveryService(gitService, gitHubApiService);
 
+            // Start update check in background (non-blocking)
+            var updateCheckService = new UpdateCheckService(gitHubApiService.HttpClient);
+            var updateCheckTask = updateCheckService.CheckForUpdateAsync(cancellationToken);
+
             // Run interactive menu
             var menu = new InteractiveMenu(
                 gitService,
                 gitHubApiService,
                 modDiscoveryService,
-                modsDirectory);
+                modsDirectory,
+                updateCheckTask);
 
             await menu.RunAsync(cancellationToken);
 

Commands/UpdateCommand.cs

@@ -31,6 +31,10 @@ public class UpdateCommand : AsyncCommand<ModPathSettings>
             var gitHubApiService = new GitHubApiService();
             var modDiscoveryService = new ModDiscoveryService(gitService, gitHubApiService);
 
+            // Start update check in background (non-blocking)
+            var updateCheckService = new UpdateCheckService(gitHubApiService.HttpClient);
+            var updateCheckTask = updateCheckService.CheckForUpdateAsync(cancellationToken);
+
             // Discover mods
             var mods = await ProgressReporter.WithStatusAsync(
                 "Scanning mods directory...",
@@ -76,6 +80,17 @@ public class UpdateCommand : AsyncCommand<ModPathSettings>
 
             ModTableRenderer.RenderUpdateSummary(results);
 
+            // Show update notification if available
+            var updateResult = await updateCheckTask;
+            if (updateResult != null)
+            {
+                AnsiConsole.WriteLine();
+                var label = updateResult.IsPrerelease ? "Pre-release available" : "Update available";
+                AnsiConsole.MarkupLine(
+                    $"[yellow bold]{label}: v{updateResult.LatestVersion}[/] [grey](current: {updateResult.CurrentVersion})[/]");
+                AnsiConsole.MarkupLine($"[grey]Download: {updateResult.ReleaseUrl}[/]");
+            }
+
             var failCount = results.Count(r => !r.Success);
             return failCount > 0 ? 1 : 0;
         }

Services/GitHubApiService.cs

@@ -15,13 +15,14 @@ public class GitHubApiService : IGitHubApiService, IDisposable
     private IReadOnlyList<RemoteRepo>? _cachedRepos;
     private DateTimeOffset _cacheTime = DateTimeOffset.MinValue;
 
+    public HttpClient HttpClient => _httpClient;
     public int? RemainingRateLimit { get; private set; }
     public DateTimeOffset? RateLimitReset { get; private set; }
 
     public GitHubApiService(HttpClient? httpClient = null)
     {
         _httpClient = httpClient ?? new HttpClient();
-        _httpClient.DefaultRequestHeaders.UserAgent.ParseAdd("FCPModUpdater/1.0");
+        _httpClient.DefaultRequestHeaders.UserAgent.ParseAdd($"FCPModUpdater/{AppVersion.SemanticVersion}");
         _httpClient.DefaultRequestHeaders.Accept.ParseAdd("application/vnd.github+json");
 
         var token = Environment.GetEnvironmentVariable("GITHUB_TOKEN");

Services/UpdateCheckService.cs

@@ -0,0 +1,96 @@
+using System.Net.Http.Json;
+using FCPModUpdater.Models;
+
+namespace FCPModUpdater.Services;
+
+public class UpdateCheckService
+{
+    private const string RepoOwner = "FalloutCollaborationProject";
+    private const string RepoName = "FCP-Mod-Updater";
+    private const string BaseUrl = "https://api.github.com";
+
+    private readonly HttpClient _httpClient;
+
+    public UpdateCheckService(HttpClient httpClient)
+    {
+        _httpClient = httpClient;
+    }
+
+    /// <summary>
+    /// Check if a newer version is available. Returns null if check fails or no update needed.
+    /// Checks both stable and prerelease versions.
+    /// </summary>
+    public async Task<UpdateCheckResult?> CheckForUpdateAsync(CancellationToken ct = default)
+    {
+        try
+        {
+            var url = $"{BaseUrl}/repos/{RepoOwner}/{RepoName}/releases?per_page=15";
+            var releases = await _httpClient.GetFromJsonAsync<List<ReleaseInfo>>(url, ct);
+
+            if (releases is null || releases.Count == 0)
+                return null;
+
+            // Find the release with the highest semver (stable or prerelease)
+            ReleaseInfo? newest = null;
+            Version? newestVersion = null;
+
+            foreach (var release in releases)
+            {
+                if (release.Draft)
+                    continue;
+
+                var tagBase = GetBaseVersion(release.TagName.TrimStart('v'));
+                if (!Version.TryParse(tagBase, out var ver))
+                    continue;
+
+                if (newestVersion is null || ver > newestVersion)
+                {
+                    newestVersion = ver;
+                    newest = release;
+                }
+            }
+
+            if (newest is null || newestVersion is null)
+                return null;
+
+            var currentBase = GetBaseVersion(AppVersion.SemanticVersion);
+            if (!Version.TryParse(currentBase, out var currentVer))
+                return null;
+
+            if (newestVersion > currentVer)
+            {
+                var latestTag = newest.TagName.TrimStart('v');
+                return new UpdateCheckResult(
+                    CurrentVersion: AppVersion.InformationalVersion,
+                    LatestVersion: latestTag,
+                    ReleaseUrl: newest.HtmlUrl,
+                    ReleaseName: newest.Name,
+                    PublishedAt: newest.PublishedAt,
+                    IsPrerelease: newest.Prerelease
+                );
+            }
+
+            return null;
+        }
+        catch
+        {
+            // Update check is non-critical — fail silently
+            return null;
+        }
+    }
+
+    private static string GetBaseVersion(string version)
+    {
+        var dashIndex = version.IndexOf('-');
+        return dashIndex >= 0 ? version[..dashIndex] : version;
+    }
+}
+
+public record UpdateCheckResult(
+    string CurrentVersion,
+    string LatestVersion,
+    string ReleaseUrl,
+    string ReleaseName,
+    DateTimeOffset PublishedAt,
+    bool IsPrerelease
+);

UI/InteractiveMenu.cs

@@ -10,19 +10,23 @@ public class InteractiveMenu
     private readonly IGitHubApiService _gitHubApiService;
     private readonly IModDiscoveryService _modDiscoveryService;
     private readonly string _modsDirectory;
+    private readonly Task<UpdateCheckResult?> _updateCheckTask;
 
     private IReadOnlyList<InstalledMod> _mods = [];
+    private bool _updateNotificationShown;
 
     public InteractiveMenu(
         IGitService gitService,
         IGitHubApiService gitHubApiService,
         IModDiscoveryService modDiscoveryService,
-        string modsDirectory)
+        string modsDirectory,
+        Task<UpdateCheckResult?> updateCheckTask)
     {
         _gitService = gitService;
         _gitHubApiService = gitHubApiService;
         _modDiscoveryService = modDiscoveryService;
         _modsDirectory = modsDirectory;
+        _updateCheckTask = updateCheckTask;
     }
 
     public async Task RunAsync(CancellationToken ct = default)
@@ -35,6 +39,21 @@ public class InteractiveMenu
             AnsiConsole.Clear();
             ModTableRenderer.RenderModTable(_mods, _gitHubApiService.RemainingRateLimit,
                 _gitHubApiService.RateLimitReset);
+
+            // Show update notification once, non-blocking
+            if (!_updateNotificationShown && _updateCheckTask.IsCompleted)
+            {
+                _updateNotificationShown = true;
+                var updateResult = await _updateCheckTask;
+                if (updateResult != null)
+                {
+                    var label = updateResult.IsPrerelease ? "Pre-release available" : "Update available";
+                    AnsiConsole.MarkupLine(
+                        $"[yellow bold]{label}: v{updateResult.LatestVersion}[/] [grey](current: {updateResult.CurrentVersion})[/]");
+                    AnsiConsole.MarkupLine($"[grey]Download: {updateResult.ReleaseUrl}[/]");
+                }
+            }
+
             AnsiConsole.WriteLine();
 
             var choice = AnsiConsole.Prompt(

packages.lock.json

@@ -29,6 +29,7 @@
           "Spectre.Console": "0.53.1"
         }
       }
-    }
+    },
+    "net10.0/linux-x64": {}
   }
 }