me-web? skeleton: Avalonia 12 app, server, packaging and CI

The first screen (online or not, a Check button, every language with a
draft notice), the desktop and Android heads, the server's /api/info and
/api/ip, a release tool that builds deb, rpm, a Windows exe, macOS zips,
a signed APK and the server, and the Gitea workflows that run it. Rules
adapted from passolo; AGPL-3.0.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012CzABvBkbcFqoHdmi8b9WB

src/MeWeb.App/Services/Localizer.cs

@@ -0,0 +1,52 @@
+using System.ComponentModel;
+using System.Globalization;
+using System.Resources;
+
+using Avalonia.Data;
+using Avalonia.Markup.Xaml;
+using Avalonia.Markup.Xaml.MarkupExtensions;
+
+namespace MeWeb.App.Services;
+
+public sealed class Localizer : INotifyPropertyChanged
+{
+  readonly ResourceManager resources = new("MeWeb.App.Strings.Strings", typeof(Localizer).Assembly);
+
+  public static Localizer Instance { get; } = new();
+
+  public event PropertyChangedEventHandler PropertyChanged;
+
+  public Language Language { get; private set; } = Languages.Fallback;
+
+  public CultureInfo Culture { get; private set; } = CultureInfo.GetCultureInfo(Languages.Fallback.Code);
+
+  public bool IsRightToLeft => Culture.TextInfo.IsRightToLeft;
+
+  public string this[string key] => resources.GetString(key, Culture) ?? key;
+
+  public string Format(string key, params object[] args) => string.Format(Culture, this[key], args);
+
+  public void SetLanguage(Language language)
+  {
+    Language = language ?? Languages.Fallback;
+    Culture = CultureInfo.GetCultureInfo(Language.Code);
+    CultureInfo.DefaultThreadCurrentCulture = CultureInfo.DefaultThreadCurrentUICulture = Culture;
+    CultureInfo.CurrentCulture = CultureInfo.CurrentUICulture = Culture;
+    PropertyChanged?.Invoke(this, new PropertyChangedEventArgs("Item[]"));
+    PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(string.Empty));
+  }
+}
+
+public sealed class TrExtension : MarkupExtension
+{
+  public TrExtension()
+  {
+  }
+
+  public TrExtension(string key) => Key = key;
+
+  public string Key { get; set; }
+
+  public override object ProvideValue(IServiceProvider serviceProvider) =>
+      new ReflectionBindingExtension($"[{Key}]") { Mode = BindingMode.OneWay, Source = Localizer.Instance }.ProvideValue(serviceProvider);
+}