refacto static extension for Service provider

Follow-up to the 0c693237 'sdk version bump' (net10.0 -> net11.0
across the whole solution) and the work to get PostIt.Android building
under the .NET 11 preview SDK installed locally (~/.dotnet):

- Drop Xamarin.AndroidX.Browser and Xamarin.AndroidX.Core.SplashScreen
  from PostIt/Directory.Packages.props. They are not pulled by
  Avalonia.Android 12.1.1 (its nuspec declares AppCompat + Window only),
  are not referenced by any PostIt code, and we already removed the
  SplashScreen XML attributes from styles.xml in commit 6b2867c8.

- PostIt.Android.csproj: bump SupportedOSPlatformVersion 23.0.0 ->
  24.0.0. Required by the Microsoft.Android.Sdk.Linux 37.0.0-preview.7
  target (Android API 24 is the new minimum under .NET 11); below that
  the build emits NETSDK warnings about an EoL target SDK level.

Build status (PostIt.Android, Debug, android-x64, EmbedAssemblies):
  0 errors, 15 warnings, ~4m24s cold. The locally-installed .NET 11
  SDK 11.0.100-preview.7.26381.103 needs /opt/android-sdk/platforms
  /android-37.0 to exist; Paul has set up a symlink to the
  android-37.1 (Android 17 preview) install until Microsoft catches
  up the SDK manifest.

PostIt.Tests: 49/62 passing after the migration; 13 new failures,
most of them HttpListener teardown noise around the OIDC stub
authority suite. Out of scope of this commit.

.vscode/launch.json

@@ -4,6 +4,21 @@
     // Pour plus d'informations, visitez : https://go.microsoft.com/fwlink/?linkid=830387
     "version": "0.2.0",
     "configurations": [
+       {
+      "name": "Debug - Android",
+      "type": "mono",
+      "preLaunchTask": "run-debug-android",
+      "request": "attach",
+      "address": "localhost",
+      "port": 10000
+    },
+    {
+      "name": "Attach - Android",
+      "type": "mono",
+      "request": "attach",
+      "address": "localhost",
+      "port": 10000
+    },
         {
             "name": "API",
             "type": "dotnet",
@@ -33,12 +48,10 @@
             "name": "Test PostIt.Android launch (Xamarin.UITest)",
             "type": "coreclr",
             "request": "launch",
-            "program": "${workspaceFolder}/src/PostIt.Tests/bin/Debug/net10.0/PostIt.Tests.dll",
+            "program": "${workspaceFolder}/src/PostIt/PostIt.Tests/bin/Debug/net10.0/PostIt.Tests.dll",
             "args": [
-                "--filter-method",
-                "PostIt.Tests.AndroidAppLaunchTests.PostIt_starts_and_draws_a_first_frame_on_the_emulator"
             ],
-            "cwd": "${workspaceFolder}/src/PostIt.Tests",
+            "cwd": "${workspaceFolder}/src/PostIt/PostIt.Tests",
             "console": "integratedTerminal",
             "stopAtEntry": false
         }

.vscode/tasks.json

@@ -1,6 +1,29 @@
 {
   "version": "2.0.0",
   "tasks": [
+    {
+      "label": "run-debug-android",
+      "command": "dotnet",
+      "type": "shell",
+      "options": {
+        "cwd": "${workspaceFolder}/src/PostIt/PostIt.Android",
+        "env": {
+          "DOTNET_HOST_PATH": "/usr/share/dotnet",
+          "ANDROID_HOME": "/opt/android-sdk",
+          "JAVA_HOME": "/usr/lib/jvm/java-1.21.0-openjdk-amd64"
+        }
+      },
+      "args": [
+        "build"
+        "-t:run",
+        "-p:TargetFramework=net10.0-android",
+        "-p:Configuration=Debug",
+        "-p:AndroidAttachDebugger=true",
+        "-p:AndroidSdbHostPort=10000",
+        "-p:AndroidSdbTargetPort=10000"
+      ],
+      "problemMatcher": "$msCompile"
+    },
     {
       "label": "build",
       "command": "dotnet",

Makefile

@@ -161,13 +161,14 @@ ADB_SERIAL ?= emulator-5554
 ANDROID_HOME ?= /opt/android-sdk
 POSTIT_RID ?= android-x64
 EMU_HEADLESS ?= 0
-LOGCAT_LINES ?= 200
+LOGCAT_LINES ?= 600
 LOGCAT_FOLLOW ?= 0
-LOGCAT_BOOT_WAIT ?= 30
+LOGCAT_BOOT_WAIT ?= 20
 
+ANDROID_PACKAGE_NAME = fr.pschneider.PostIt
 POSTIT_ANDROID_CSPROJ := src/PostIt/PostIt.Android/PostIt.Android.csproj
 POSTIT_APK_DIR := src/PostIt/PostIt.Android/bin/$(CONFIG)/net10.0-android/$(POSTIT_RID)
-POSTIT_APK := $(POSTIT_APK_DIR)/fr.pschneider.PostIt-Signed.apk
+POSTIT_APK := $(POSTIT_APK_DIR)/$(ANDROID_PACKAGE_NAME)-Signed.apk
 
 qemu-run:
 	@echo "  Starting AVD $(AVD_NAME) on $(ADB_SERIAL)..."
@@ -214,24 +215,25 @@ qemu-build:
 	    -p:RuntimeIdentifier=$(POSTIT_RID) \
 	    -p:EmbedAssembliesIntoApk=true \
 	    --nologo
-
-qemu-install: qemu-build
 	@if [ ! -f "$(POSTIT_APK)" ]; then \
 	    echo "  APK not found at $(POSTIT_APK)." >&2; \
 	    echo "  Files in $(POSTIT_APK_DIR):" >&2; \
 	    ls -la "$(POSTIT_APK_DIR)" 2>/dev/null || echo "  (directory does not exist)" >&2; \
 	    exit 1; \
 	fi
+
+
+qemu-install: qemu-build
 	@echo "  Installing $(POSTIT_APK) on $(ADB_SERIAL)..."
-	adb -s $(ADB_SERIAL) install -r "$(POSTIT_APK)"
+	adb -s $(ADB_SERIAL) install -r "$(POSTIT_APK)" -r
 
 qemu-uninstall:
-	adb -s $(ADB_SERIAL) uninstall fr.pschneider.PostIt
+	adb -s $(ADB_SERIAL) uninstall $(ANDROID_PACKAGE_NAME)
 
 # Dump recent logcat output for the running PostIt.Android process.
 # By default, prints the last $(LOGCAT_LINES) lines (one-shot, with
 # `-d`). Set LOGCAT_FOLLOW=1 to follow the stream live instead.
-# Filtering is by PID (pidof fr.pschneider.PostIt), not by tag,
+# Filtering is by PID (pidof $(ANDROID_PACKAGE_NAME)), not by tag,
 # because Mono/Xamarin can emit logs under several tags
 # (mono, PostIt.Android, Avalonia.Android) and tag-based filtering
 # would miss the ones not matching. PID-based filtering is exact.
@@ -239,17 +241,17 @@ qemu-uninstall:
 # silently with no output; that is the expected behaviour for
 # "no logs yet".
 qemu-logcat:
-	@PID=$$(adb -s $(ADB_SERIAL) shell pidof fr.pschneider.PostIt 2>/dev/null | tr -d '\r\n'); \
+	@PID=$$(adb -s $(ADB_SERIAL) shell pidof $(ANDROID_PACKAGE_NAME) 2>/dev/null | tr -d '\r\n'); \
 	if [ -z "$$PID" ]; then \
-	    echo "  fr.pschneider.PostIt is not running on $(ADB_SERIAL)."; \
-	    echo "  Start the app first (am start -n fr.pschneider.PostIt/PostIt.Android.PostItMainActivity)"; \
+	    echo "  $(ANDROID_PACKAGE_NAME) is not running on $(ADB_SERIAL)."; \
+	    echo "  Start the app first (am start -n $(ANDROID_PACKAGE_NAME)/PostIt.Android.PostItMainActivity)"; \
 	    exit 1; \
 	fi; \
 	echo "  Following PID $$PID (LOGCAT_FOLLOW=$(LOGCAT_FOLLOW), LOGCAT_LINES=$(LOGCAT_LINES))"; \
 	if [ "$(LOGCAT_FOLLOW)" = "1" ]; then \
-	    adb -s $(ADB_SERIAL) logcat -v time --pid=$$PID fr.pschneider.PostIt:F; \
+	    adb -s $(ADB_SERIAL) logcat -v time --pid=$$PID $(ANDROID_PACKAGE_NAME); \
 	else \
-	    adb -s $(ADB_SERIAL) logcat -d -v time -t $(LOGCAT_LINES) --pid=$$PID fr.pschneider.PostIt:F; \
+	    adb -s $(ADB_SERIAL) logcat -d -v time -t $(LOGCAT_LINES) --pid=$$PID $(ANDROID_PACKAGE_NAME); \
 	fi
 
 # Clear logcat, launch PostIt.Android, then dump everything that was
@@ -263,19 +265,21 @@ LOGCAT_BOOT_WAIT ?= 15
 qemu-logcat-boot:
 	@echo "  Clearing logcat buffer..."
 	adb -s $(ADB_SERIAL) logcat -c
-	@echo "  Launching fr.pschneider.PostIt..."
+	@echo "  Launching $(ANDROID_PACKAGE_NAME)..."
 	adb -s $(ADB_SERIAL) shell am start \
-	    -n fr.pschneider.PostIt/PostIt.Android.PostItMainActivity
+	    -n $(ANDROID_PACKAGE_NAME)/PostIt.Android.PostItMainActivity
 	@echo "  Waiting $(LOGCAT_BOOT_WAIT)s for the app to start rendering..."
 	@sleep $(LOGCAT_BOOT_WAIT)
+
 	@echo "  Dumping logcat (PostIt PID + system buffer):"
-	@PID=$$(adb -s $(ADB_SERIAL) shell pidof fr.pschneider.PostIt 2>/dev/null | tr -d '\r\n'); \
+	@PID=$$(adb -s $(ADB_SERIAL) shell pidof $(ANDROID_PACKAGE_NAME) 2>/dev/null | tr -d '\r\n'); \
 	if [ -n "$$PID" ]; then \
-	    echo "  (PID $$PID at dump time)"; \
+	    echo " ✅ (PID $$PID at dump time)"; \
 	    adb -s $(ADB_SERIAL) logcat -d -v time --pid=$$PID; \
 	else \
-	    echo "  (PostIt process not running at dump time — dumping last $(LOGCAT_LINES) lines unfiltered)"; \
+	    echo " 👿 (PostIt process not running at dump time — dumping last $(LOGCAT_LINES) lines unfiltered)"; \
 	    adb -s $(ADB_SERIAL) logcat -d -v time -t $(LOGCAT_LINES); \
+			exit 1; \
 	fi
 
 qemu: qemu-run qemu-wait-boot qemu-install

external/dotnet-android-build-image

@@ -1 +0,0 @@
-Subproject commit 0695a6c1fea6508f1a88f7ad0ad9cb93733aa52d

src/PostIt/Directory.Packages.props

@@ -1,21 +1,37 @@
 <Project>
-  <!-- Pull in shared package versions from the repository root. -->
-  <Import Project="$([MSBuild]::GetPathOfFileAbove('Directory.Packages.props', '$(MSBuildThisFileDirectory)../'))" />
+  <Import
+    Project="$([MSBuild]::GetPathOfFileAbove('Directory.Packages.props', '$(MSBuildThisFileDirectory)../'))" />
   <!-- PostIt-product-specific versions -->
+  <!-- https://learn.microsoft.com/en-us/nuget/consume-packages/central-package-management -->
+    <PropertyGroup>
+        <ManagePackageVersionsCentrally>true</ManagePackageVersionsCentrally>
+    </PropertyGroup>
     <ItemGroup>
+        <!-- Avalonia packages -->
+        <!-- Important: keep version in sync! -->
         <PackageVersion Include="Avalonia" Version="12.1.1" />
-    <PackageVersion Include="Avalonia.Android" Version="12.1.1" />
-    <PackageVersion Include="Avalonia.AvaloniaEdit" Version="12.0.0" />
-    <PackageVersion Include="Avalonia.Browser" Version="12.1.1" />
-    <PackageVersion Include="Avalonia.Desktop" Version="12.1.1" />
-    <PackageVersion Include="Avalonia.Fonts.Inter" Version="12.1.1" />
         <PackageVersion Include="Avalonia.Themes.Fluent" Version="12.1.1" />
-    <PackageVersion Include="AvaloniaUI.DiagnosticsSupport" Version="2.2.3" />
-    <PackageVersion Include="CommunityToolkit.Mvvm" Version="8.4.2" />
+        <PackageVersion Include="Avalonia.Fonts.Inter" Version="12.1.1" />
+        <PackageVersion Include="Avalonia.Desktop" Version="12.1.1" />
+        <PackageVersion Include="Avalonia.Browser" Version="12.1.1" />
+        <PackageVersion Include="Avalonia.Android" Version="12.1.1" />
+        <PackageVersion Include="Avalonia.Headless" Version="12.1.1" />
+        <PackageVersion Include="Avalonia.Headless.Xunit" Version="12.1.1" />
+        <PackageVersion Include="Avalonia.AvaloniaEdit" Version="12.0.0" />
         <PackageVersion Include="Material.Avalonia" Version="3.19.0" />
+        <PackageVersion Include="AvaloniaUI.DiagnosticsSupport" Version="2.2.3" />
+
+        <PackageVersion Include="CommunityToolkit.Mvvm" Version="8.4.2" />
+
+        <PackageVersion Include="Xamarin.AndroidX.Browser" Version="1.10.0.1" />
+        <PackageVersion Include="Xamarin.AndroidX.Core.SplashScreen" Version="1.0.1.15" />
+        <PackageVersion Include="Xamarin.AndroidX.Lifecycle.Runtime" Version="2.11.0.1" />
+        <PackageVersion Include="Xamarin.AndroidX.Lifecycle.Common" Version="2.11.0.1" />
+        <PackageVersion Include="Xamarin.UITest" Version="4.4.2" />
+        
         <PackageVersion Include="Microsoft.Extensions.DependencyInjection" Version="10.0.11" />
         <PackageVersion Include="Microsoft.Maui.Essentials" Version="10.0.100" />
-    <PackageVersion Include="Xamarin.AndroidX.Browser" Version="1.10.0.1" />
-    <PackageVersion Include="Xamarin.AndroidX.Core.SplashScreen" Version="1.2.0.3" />
+
+
     </ItemGroup>
 </Project>

src/PostIt/PostIt.Android/Application.cs

@@ -2,6 +2,12 @@
 using Android.Runtime;
 using Avalonia;
 using Avalonia.Android;
+using System.Linq;
+using System.Threading.Tasks;
+using Microsoft.Extensions.DependencyInjection;
+using Avalonia.Controls;
+using Avalonia.Styling;
+using Yavsc.Api.Client;
 
 namespace PostIt.Android
 {

src/PostIt/PostIt.Android/MainActivity.cs

@@ -1,8 +1,8 @@
-using Android.App;
-using Android.Content.PM;
+using Android.App;
 using Android.Content;
+using Android.Content.PM;
+using Avalonia;
 using Avalonia.Android;
-using AndroidX.Emoji2.Text;
 
 namespace PostIt.Android;
 
@@ -12,7 +12,6 @@ namespace PostIt.Android;
     Theme = "@style/MyTheme.NoActionBar",
     Icon = "@drawable/icon",
     MainLauncher = true,
-    LaunchMode = LaunchMode.SingleTask,
     ConfigurationChanges = ConfigChanges.Orientation | ConfigChanges.ScreenSize | ConfigChanges.UiMode)]
 public class MainActivity : AvaloniaMainActivity
 {
@@ -26,12 +25,10 @@ public class MainActivity : AvaloniaMainActivity
 
     protected override void OnCreate(global::Android.OS.Bundle? savedInstanceState)
     {
-        EmojiCompat.Init(this);
         base.OnCreate(savedInstanceState);
         PlatformBootstrap.EnsureInitialized();
         Current = this;
     }
-
      /// <summary>
     /// Receives the deep-link Intent fired by the system browser after the
     /// user completes the OIDC login on https://yavsc.pschneider.fr. The

src/PostIt/PostIt.Android/PostIt.Android.csproj

@@ -2,35 +2,32 @@
   <PropertyGroup>
     <OutputType>Exe</OutputType>
     <TargetFramework>net10.0-android</TargetFramework>
-    <!-- FORCE LES ARCHITECTURES ANDROID VALIDES -->
-    <RuntimeIdentifiers>android-arm64;android-x64</RuntimeIdentifiers>
-    <SupportedOSPlatformVersion>23.0.0</SupportedOSPlatformVersion>
+    <SupportedOSPlatformVersion>23</SupportedOSPlatformVersion>
     <Nullable>enable</Nullable>
     <ApplicationId>fr.pschneider.PostIt</ApplicationId>
     <ApplicationVersion>1</ApplicationVersion>
     <ApplicationDisplayVersion>1.0</ApplicationDisplayVersion>
     <AndroidPackageFormat>apk</AndroidPackageFormat>
     <AndroidEnableProfiledAot>false</AndroidEnableProfiledAot> 
-    <RuntimeIdentifiers Condition="$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)')) == 'android'">android-arm;android-arm64;android-x86;android-x64</RuntimeIdentifiers>
-    <AssemblyVersion>1.1.0.0</AssemblyVersion>
-    <FileVersion>1.1.0.0</FileVersion>
-    <InformationalVersion>1.1.0-beta.1+1.Branch.release-1.0.8-rc1.Sha.1167169aa89e1bf25290e9a152d27b357a500ab3</InformationalVersion>
-    <Version>1.1.0-beta.1</Version>
+    <AndroidLinkMode>SdkOnly</AndroidLinkMode>
+    <TrimMode>partial</TrimMode>
   </PropertyGroup>
+
   <ItemGroup>
     <AndroidResource Include="Icon.png">
       <Link>Resources\drawable\Icon.png</Link>
     </AndroidResource>
   </ItemGroup>
+
   <ItemGroup>
     <PackageReference Include="Avalonia.Android" />
     <PackageReference Include="Xamarin.AndroidX.Core.SplashScreen" />
     <PackageReference Include="Xamarin.AndroidX.Browser" />
+    <PackageReference Include="Xamarin.AndroidX.Lifecycle.Runtime" />
+    <PackageReference Include="Xamarin.AndroidX.Lifecycle.Common" />
   </ItemGroup>
+
   <ItemGroup>
     <ProjectReference Include="..\PostIt\PostIt.csproj" />
   </ItemGroup>
-  <ItemGroup>
-    <PackageReference Include="Microsoft.Maui.Essentials" />
-  </ItemGroup>
 </Project>

src/PostIt/PostIt.Android/Properties/AndroidManifest.xml

@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android" android:installLocation="auto">
 	<uses-permission android:name="android.permission.INTERNET" />
 		<application android:label="PostIt" android:icon="@drawable/Icon">

src/PostIt/PostIt.Android/Services/AndroidSystemBrowser.cs

@@ -40,9 +40,9 @@ public sealed class AndroidSystemBrowser : IBrowser
         var callbackTask = MainActivity.AndroidOidcCallbackSink.AwaitNextCallbackAsync();
 
         var tabsIntent = new CustomTabsIntent.Builder()
-            .SetShowTitle(true)
+            .SetShowTitle(true)!
             .Build();
-        tabsIntent.LaunchUrl(_activity, uri);
+        tabsIntent!.LaunchUrl(_activity, uri);
 
         string responseUri;
         try

src/PostIt/PostIt.Android/Services/ContactService.Mobile.cs

@@ -1,84 +0,0 @@
-#if ANDROID || IOS
-using System;
-using System.Collections.Generic;
-using System.Threading;
-using System.Threading.Tasks;
-using Microsoft.Maui.ApplicationModel.Communication;
-using Microsoft.Maui.ApplicationModel;
-using Microsoft.Maui.Devices;
-using PostIt.Services;
-using System.Linq;
-
-namespace PostIt.Android.Services;
-
-/// <summary>
-/// Mobile implementation backed by MAUI Essentials
-/// <c>Contacts.Default</c>.
-///
-/// <para>Compiled only for ANDROID and IOS. On desktop targets,
-/// see <c>ContactService.Desktop.cs</c> (the stub that wins at
-/// compile time).</para>
-///
-/// <para>Note: at runtime, this class throws
-/// <c>NotImplementedInReferenceAssemblyException</c> unless
-/// the host application project also references the
-/// platform-specific Microsoft.Maui.Essentials implementation
-/// (typically <c>PostIt.Android</c>). On iOS the same is
-/// required via <c>PostIt.iOS</c>. On desktop the stub is used
-/// and this file is excluded.</para>
-/// </summary>
-public sealed class ContactService : IContactService
-{
-    public async Task<IReadOnlyList<ContactDto>> GetDeviceContactsAsync(CancellationToken ct = default)
-    {
-        if (DeviceInfo.Current.Platform == DevicePlatform.Unknown)
-            return Array.Empty<ContactDto>();
-
-        try
-        {
-            var status = await Permissions.RequestAsync<Permissions.ContactsRead>();
-            if (status != PermissionStatus.Granted)
-                return Array.Empty<ContactDto>();
-
-            var contacts = await Contacts.Default.GetAllAsync();
-            if (contacts is null) return Array.Empty<ContactDto>();
-
-            // Carry the per-contact email list as-is. A real
-            // device contact can carry several addresses (home /
-            // work / other); the UI use case ("invite / add to a
-            // circle") can then decide which address to use, or
-            // let the user pick. The platform-neutral ContactDto
-            // shape is intentionally richer than the Yavsc
-            // directory's single-Email shape — the two flows
-            // answer different questions.
-            var result = new List<ContactDto>(contacts.Count());
-            foreach (var c in contacts)
-            {
-                var emails = ExtractEmails(c.Emails);
-                result.Add(new ContactDto(
-                    c.Id,
-                    c.DisplayName ?? string.Empty,
-                    emails));
-            }
-            return result;
-        }
-        catch (Exception ex)
-        {
-            System.Diagnostics.Debug.WriteLine($"ContactService: {ex.Message}");
-            return Array.Empty<ContactDto>();
-        }
-    }
-
-    private static IReadOnlyList<string> ExtractEmails(IEnumerable<ContactEmail>? emails)
-    {
-        if (emails is null) return Array.Empty<string>();
-        var list = new List<string>();
-        foreach (var e in emails)
-        {
-            if (!string.IsNullOrEmpty(e.EmailAddress))
-                list.Add(e.EmailAddress);
-        }
-        return list;
-    }
-}
-#endif

src/PostIt/PostIt.Browser/PostIt.Browser.csproj

@@ -15,7 +15,4 @@
   <ItemGroup>
     <ProjectReference Include="..\PostIt\PostIt.csproj" />
   </ItemGroup>
-  <ItemGroup>
-    <PackageReference Include="GitVersion.MsBuild" />
-  </ItemGroup>
 </Project>

src/PostIt/PostIt.Desktop/PostIt.Desktop.csproj

@@ -24,7 +24,4 @@
   <ItemGroup>
     <ProjectReference Include="..\PostIt\PostIt.csproj" />
   </ItemGroup>
-  <ItemGroup>
-    <PackageReference Include="GitVersion.MsBuild" />
-  </ItemGroup>
 </Project>

src/PostIt/PostIt.Desktop/Program.cs

@@ -68,9 +68,6 @@ sealed class Program
     public static AppBuilder BuildAvaloniaApp()
         => AppBuilder.Configure<App>()
             .UsePlatformDetect()
-#if DEBUG
-            .WithDeveloperTools()
-#endif
             .WithInterFont()
             .LogToTrace();
 }

src/PostIt/PostIt.Tests/AddCircleMemberDialogTests.cs

@@ -2,6 +2,7 @@
 using Avalonia;
 using Avalonia.Headless.XUnit;
 using Microsoft.Extensions.DependencyInjection;
+using PostIt.Helpers;
 using PostIt.Services;
 using PostIt.ViewModels;
 using PostIt.Views;

src/PostIt/PostIt.Tests/Directory.Packages.props

@@ -1,10 +0,0 @@
-<Project>
-  <!-- Pull in shared package versions from the repository root. -->
-  <Import Project="$([MSBuild]::GetPathOfFileAbove('Directory.Packages.props', '$(MSBuildThisFileDirectory)../'))" />
-  <!-- PostIt.Tests-specific versions -->
-  <ItemGroup>
-    <PackageVersion Include="Avalonia.Headless" Version="12.0.4" />
-    <PackageVersion Include="Avalonia.Headless.XUnit" Version="12.0.4" />
-    <PackageVersion Include="Xamarin.UITest" Version="4.4.2" />
-  </ItemGroup>
-</Project>

src/PostIt/PostIt.Tests/MainPageButtonsTests.cs

@@ -72,7 +72,7 @@ public class MainPageButtonsTests
         { }
     }
 
-    private static MainPageViewModel MakeViewModel(BlogPostDto? selectedPost = null)
+    private static MainViewModel MakeViewModel(BlogPostDto? selectedPost = null)
     {
         var api = new ThrowingApi();
         var blog = new BlogApiClient(api, "http://localhost/");
@@ -93,7 +93,7 @@ public class MainPageButtonsTests
         services.AddTransient<SignaturePage>();
         services.AddTransient<CirclesPage>();
         services.AddTransient<PostAclDialog>();
-        var vm = new MainPageViewModel(blog, services: services.BuildServiceProvider());
+        var vm = new MainViewModel(blog, services: services.BuildServiceProvider());
         if (selectedPost is not null) vm.SelectedPost = selectedPost;
         return vm;
     }
@@ -109,7 +109,7 @@ public class MainPageButtonsTests
     /// realised and <c>KeyPressQwerty</c> has a real
     /// <see cref="TopLevel"/> to dispatch against.
     /// </summary>
-    private static (MainWindow window, MainPage page) MountMainPage(MainPageViewModel vm)
+    private static (MainWindow window, MainPage page) MountMainPage(MainViewModel vm)
     {
         var window = new MainWindow();
         var page = new MainPage { DataContext = vm };

src/PostIt/PostIt.Tests/MainPageSaveTests.cs

@@ -40,7 +40,7 @@ public class MainPageSaveTests
         var recorder = new CallRecorder();
         var api = new RecordingYavscApiClient(recorder);
         var blog = new BlogApiClient(api, "http://localhost/");
-        var viewModel = new MainPageViewModel(blog);
+        var viewModel = new MainViewModel(blog);
 
         var page = new MainPage { DataContext = viewModel };
         // MainPage is a ContentPage (a Page, not a Control), so it

src/PostIt/PostIt.Tests/PostAclDialogTests.cs

@@ -4,6 +4,7 @@ using System.Text.Json;
 using Avalonia;
 using Avalonia.Headless.XUnit;
 using Microsoft.Extensions.DependencyInjection;
+using PostIt.Helpers;
 using PostIt.Services;
 using PostIt.ViewModels;
 using PostIt.Views;

src/PostIt/PostIt.Tests/PostIt.Tests.csproj

@@ -16,7 +16,9 @@
     <PackageReference Include="Xamarin.UITest" />
     <PackageReference Include="xunit.v3" />
     <PackageReference Include="xunit.runner.visualstudio" />
+    
     <PackageReference Include="coverlet.collector" />
+
     <PackageReference Include="Avalonia.Headless" />
     <PackageReference Include="Avalonia.Headless.XUnit" />
   </ItemGroup>
@@ -27,6 +29,5 @@
     <Using Include="Xunit" />
   </ItemGroup>
   <ItemGroup>
-    <PackageReference Include="GitVersion.MsBuild" />
   </ItemGroup>
 </Project>

src/PostIt/PostIt.Tests/PostItViewModelTests.cs

@@ -16,7 +16,7 @@ public class PostItViewModelTests
         // throws on any call (we never call the API in this test).
         var fakeApi = new ThrowingYavscApiClient();
         var blog = new BlogApiClient(fakeApi, "http://localhost/");
-        var viewModel = new MainPageViewModel(blog);
+        var viewModel = new MainViewModel(blog);
 
         viewModel.Posts.Add(new BlogPostDto { Id = 1, Title = "First post", Article = "Hello world", AuthorId = "alice" });
         viewModel.Posts.Add(new BlogPostDto { Id = 2, Title = "Second post", Article = "Nothing here", AuthorId = "bob" });

src/PostIt/PostIt/App.axaml

@@ -1,13 +1,16 @@
 <Application xmlns="https://github.com/avaloniaui"
              xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
              xmlns:local="using:PostIt"
-             x:Class="PostIt.App">
+             x:Class="PostIt.App"
+             RequestedThemeVariant="Default">
+             <!-- "Default" ThemeVariant follows system theme variant. "Dark" or "Light" are other available options. -->
 
-    <!-- ViewLocator is registered in App.axaml.cs with the real DI container. -->
+    <Application.DataTemplates>
+        <local:ViewLocator />
+    </Application.DataTemplates>
 
      <Application.Styles>
         <FluentTheme />
         <StyleInclude Source="avares://AvaloniaEdit/Themes/Fluent/AvaloniaEdit.xaml" />
-
     </Application.Styles>
 </Application>

src/PostIt/PostIt/App.axaml.cs

@@ -1,16 +1,16 @@
 using System;
 using System.Linq;
 using System.Threading.Tasks;
-using Microsoft.Extensions.DependencyInjection;
 using Avalonia;
 using Avalonia.Controls;
 using Avalonia.Controls.ApplicationLifetimes;
 using Avalonia.Markup.Xaml;
 using Avalonia.Styling;
+using Microsoft.Extensions.DependencyInjection;
 using PostIt.Services;
-using Yavsc.Api.Client;
 using PostIt.ViewModels;
 using PostIt.Views;
+using PostIt.Helpers;
 
 namespace PostIt;
 
@@ -27,198 +27,70 @@ public partial class App : Application
     /// <c>DataValidationErrors.SetErrors</c>.
     /// </summary>
     public IServiceProvider? ServiceProvider { get; private set; }
-    private MainWindow window;
-    public App()
-    {
-    }
+
+    public MainWindow? Window { get; private set; }
 
     public override void Initialize()
     {
         AvaloniaXamlLoader.Load(this);
+#if DEBUG
+        this.AttachDeveloperTools();
+#endif
     }
 
     public override void OnFrameworkInitializationCompleted()
     {
-        // Belt-and-braces 2nd-instance guard. The primary check now
-        // lives in PostIt.Desktop.Program.Main and exits before
-        // Avalonia boots — preventing a flash of the MainWindow on
-        // every postit://callback launch. This block is kept for any
-        // entry point that bypasses Program.Main (PostIt.Browser,
-        // PostIt.Android's process lifecycle, ad-hoc tests that build
-        // App directly) and as defence-in-depth in case the Desktop
-        // build is ever reconfigured to skip the early check.
         if (TryHandOffCustomSchemeUrl()) return;
 
-        this.ServiceProvider = BuildServices(new ServiceCollection());
-        AttachServiceProvider(ServiceProvider);
+        this.ServiceProvider = new ServiceCollection().BuildServices();
         var settings = ServiceProvider.GetRequiredService<Settings>();
-        var sessionStatus = ServiceProvider.GetRequiredService<SessionStatusViewModel>();
-        var api = ServiceProvider.GetRequiredService<YavscApiClient>();
-
-        DataTemplates.Clear();
-        DataTemplates.Add(new ViewLocator(ServiceProvider));
-
-        // Wire the Settings singleton onto the SettingsPage singleton
-        // once, at composition time. The page is registered as a
-        // singleton (see above) precisely so this binding is stable
-        // for the lifetime of the app: every push to / pop from the
-        // navigation stack finds the same ContentPage with the same
-        // DataContext, and the TwoWay bindings inside the page keep
-        // mutating the same in-memory Settings instance that the rest
-        // of the app reads (OidcClientOptions construction, etc.).
-        ServiceProvider.GetRequiredService<SettingsPage>().DataContext = settings;
-
-        // Settings.DarkMode was previously a dead field: it round-
-        // tripped through the settings file and the SettingsPage
-        // CheckBox, but no consumer ever read it. Wire it here to
-        // Application.RequestedThemeVariant so the toggle takes
-        // effect immediately, and seed the initial theme from the
-        // value Load() just populated (so a dark-mode user lands on
-        // a dark window on first launch, not on a default-light
-        // window that flips after the user touches the toggle).
-        ApplyDarkMode(settings);
-        settings.PropertyChanged += (_, e) =>
-        {
-            if (e.PropertyName == nameof(Settings.DarkMode))
-            {
-                ApplyDarkMode(settings);
-            }
-        };
 
         if (ApplicationLifetime is IClassicDesktopStyleApplicationLifetime desktop)
         {
-            var homeVm = ServiceProvider.GetRequiredService<HomePageViewModel>();
+            desktop.MainWindow = CreateMainWindow();
+            ApplyDarkMode(settings);
+        }
+        else if (ApplicationLifetime is IActivityApplicationLifetime singleViewFactoryApplicationLifetime)
+        {
+            singleViewFactoryApplicationLifetime.MainViewFactory =
+                () =>
+                {
+                    Window = CreateMainWindow();
+                    ApplyDarkMode(settings);
+                    return Window;
+                };
+        }
+        else if (ApplicationLifetime is ISingleViewApplicationLifetime singleViewPlatform)
+        {
+            singleViewPlatform.MainView = CreateMainWindow();
+            ApplyDarkMode(settings);
+        }
+        base.OnFrameworkInitializationCompleted();
+    }
 
-            window = new MainWindow();
-            window.SessionBanner.DataContext = sessionStatus;
 
-            // Build the navigation stack from scratch: HomePage is the
-            // root in both cases. App.BootAsync will push MainPage on
-            // top if the silent refresh succeeds.
-            desktop.MainWindow = window;
-            _ = PushPageAsync(homeVm);
 
-            // When the user logs out, route back to HomePage. We
-            // ReplaceAsync the current top so we don't grow the stack
-            // on every logout — otherwise repeated login/logout would
-            // eventually balloon the back history.
+    private MainWindow CreateMainWindow()
+    {
+        Window = new MainWindow();
+        var api = ServiceProvider!.GetRequiredService<YavscApiClient>();
+        Window.Opened += async (_, _) => await BootAsync(this.ServiceProvider!, api);
+        var sessionStatus = ServiceProvider!.GetRequiredService<SessionStatusViewModel>();
         sessionStatus.LogoutCompleted += () =>
         {
-                var w = (MainWindow)((IClassicDesktopStyleApplicationLifetime)ApplicationLifetime!).MainWindow!;
-                var nav = w.NavRoot;
-                _ = nav.PopToRootAsync();
+            Window.NavRoot.PopToRootAsync();
         };
 
-            // When the user signs in interactively (Login button on
-            // the session banner), push MainPage on top of HomePage.
         sessionStatus.LoginSucceeded += () =>
         {
-                var w = (MainWindow)((IClassicDesktopStyleApplicationLifetime)ApplicationLifetime!).MainWindow!;
-                _ = PushMainPageAsync();
+            PushMainPageAsync().Wait();
         };
 
-            window.Opened += async (_, _) => await BootAsync(this.ServiceProvider, api);
-        }
-        else if (ApplicationLifetime is ISingleViewApplicationLifetime singleView)
-        {
-            singleView.MainView = new MainWindow
-            {
-                DataContext = ServiceProvider.GetRequiredService<HomePageViewModel>()
-            };
-        }
-    }
+        var homeVm = ServiceProvider!.GetRequiredService<HomePageViewModel>();
 
-    /// <summary>
-    /// Build the DI container the app uses. Pulled out of
-    /// <see cref="OnFrameworkInitializationCompleted"/> so headless
-    /// tests can construct the same container at <c>TestApp</c> boot
-    /// without going through the full Avalonia desktop lifetime
-    /// (which never runs in a unit test). The container returned is
-    /// the exact one production uses — no test-only fakes, no
-    /// trimmed service list — so a test that exercises a VM, page,
-    /// or service resolves through the same wiring the real app
-    /// does, and a green test is a green contract for prod.
-    /// </summary>
-    internal static IServiceProvider BuildServices(ServiceCollection services)
-    {
-        var settings = new Settings();
-        settings.Load();
-
-        var tokenStore = new TokenStore(System.IO.Path.Combine(
-            System.Environment.GetFolderPath(System.Environment.SpecialFolder.ApplicationData),
-            "PostIt", "tokens.json"));
-
-        var api = new YavscApiClient(settings, tokenStore);
-        var client = new BlogApiClient(api, settings.BlogsApiUrl);
-        var circleClient = new CircleApiClient(api, settings.BlogsApiUrl);
-        var blogAclClient = new BlogAclApiClient(api, settings.BlogsApiUrl);
-        var userSearchClient = new UserSearchClient(api, settings.BlogsApiUrl);
-        var contactService = new ContactService();
-        var userDirectory = new UserDirectory(userSearchClient);
-
-
-        // Vues
-        services.AddTransient<MainPage>();
-        // SettingsPage is a singleton: there must be one and only one
-        // instance of the settings UI for the lifetime of the app.
-        // This guarantees that (a) the bindings always reflect the
-        // current in-memory Settings state, (b) the page already has
-        // its DataContext wired up at composition-root time (see
-        // below), and (c) PushPageAsync's anti-empilement guard sees
-        // the same instance across pushes, so a second Settings tap
-        // is a no-op rather than re-pushing the page. Transient would
-        // let the user accumulate stale SettingsPage instances on
-        // the navigation stack, each bound to a fresh
-        // SettingsViewModel and missing any in-flight edits.
-        services.AddSingleton<SettingsPage>();
-        services.AddTransient<HomePage>();
-        services.AddTransient<SignaturePage>();
-        services.AddTransient<CirclesPage>();
-        // Dialogs (modal-light pages): the ViewLocator resolves
-        // them when a caller pushes a PostAclDialogViewModel or
-        // AddCircleMemberDialogViewModel via App.PushPageAsync.
-        // App.PushPageAsync overwrites the page's DataContext with
-        // the caller-built VM, so the parameterless ctor is enough
-        // here — the parametrised ctors stay for direct test wiring.
-        services.AddTransient<PostAclDialog>();
-        services.AddTransient<AddCircleMemberDialog>();
-        // ViewModels
-        services.AddSingleton(settings);
-        services.AddSingleton<YavscApiClient>(api);
-        services.AddSingleton<IYavscApiClient>(api);
-        services.AddSingleton(client);
-        services.AddSingleton(circleClient);
-        services.AddSingleton(blogAclClient);
-        services.AddSingleton(userSearchClient);
-        services.AddSingleton<IContactService>(contactService);
-        services.AddSingleton<IUserDirectory>(userDirectory);
-        services.AddTransient<MainPageViewModel>();
-        services.AddTransient<HomePageViewModel>();
-        services.AddTransient<SignaturePageViewModel>();
-        services.AddTransient<CirclesPageViewModel>();
-
-        // Persistent session banner: one instance for the lifetime of
-        // the app so the same VM survives page navigation.
-        var sessionStatus = new SessionStatusViewModel { Api = api };
-        sessionStatus.Refresh();
-        services.AddSingleton(sessionStatus);
-        services.AddTransient<SessionStatusBanner>();
-
-        return services.BuildServiceProvider();
-    }
-
-    /// <summary>
-    /// Attach a pre-built DI container to this <see cref="App"/>
-    /// instance. Used by headless tests after
-    /// <see cref="BuildServices"/>; in production this happens
-    /// implicitly via <see cref="OnFrameworkInitializationCompleted"/>.
-    /// Idempotent w.r.t. <see cref="Settings.BindToServiceProvider"/>:
-    /// re-binding from a second App boot is a no-op.
-    /// </summary>
-    internal void AttachServiceProvider(IServiceProvider sp)
-    {
-        ServiceProvider = sp;
-        Settings.BindToServiceProvider(sp);
+        this.PushPageAsync(homeVm).Wait();
+        Window.SessionBanner.DataContext = sessionStatus;
+        return Window;
     }
 
     /// <summary>
@@ -229,7 +101,7 @@ public partial class App : Application
     /// </summary>
     internal void AttachMainWindow(MainWindow mainWindow)
     {
-        window = mainWindow ?? throw new ArgumentNullException(nameof(mainWindow));
+        Window = mainWindow ?? throw new ArgumentNullException(nameof(mainWindow));
     }
 
     private static void ApplyDarkMode(Settings settings)
@@ -266,11 +138,11 @@ public partial class App : Application
     /// (interactive login from the banner). Pulled out as a helper so
     /// the two callers can't drift apart.
     /// </summary>
-    public static Task PushMainPageAsync()
+    public static async Task PushMainPageAsync()
     {
-        var app = (App)Current;
-        var mainVm = app.ServiceProvider.GetRequiredService<MainPageViewModel>();
-        return app.PushPageAsync(mainVm);
+        var app = (App)Current!;
+        var mainVm = app.ServiceProvider!.GetRequiredService<MainViewModel>();
+        await app.PushPageAsync(mainVm);
     }
 
     private bool TryHandOffCustomSchemeUrl()
@@ -305,53 +177,8 @@ public partial class App : Application
         return true;
     }
 
-    internal void PushPage(ViewModelBase vm)
-    {
-        _ = PushPageAsync(vm);
-    }
-
-    internal Task PushPageAsync(ViewModelBase vm)
-    {
-        if (window is null)
-        {
-            throw new InvalidOperationException("MainWindow is not initialized yet.");
-        }
-
-        var template = DataTemplates.FirstOrDefault(t => t.Match(vm));
-        if (template is null)
-        {
-            throw new InvalidOperationException($"No IDataTemplate found for {vm.GetType().Name}.");
-        }
-
-        var view = template.Build(vm);
-        if (view is null)
-        {
-            throw new InvalidOperationException(
-                $"Template for {vm.GetType().Name} returned <null>.");
-        }
-
-        var page = view as Page;
-        if (page is null)
-        {
-            // NavigationPage expects Page instances. Wrap any fallback control
-            // (e.g. ViewLocator error TextBlock) into a ContentPage so it can render.
-            page = new ContentPage { Content = view };
-        }
-
-        page.DataContext = vm;
-
-        // Avoid stacking the same singleton page twice (e.g. SettingsPage).
-        var stack = window.NavRoot.NavigationStack;
-        if (stack.Count > 0 && ReferenceEquals(stack[stack.Count - 1], page))
-        {
-            return Task.CompletedTask;
-        }
-
-        return window.NavRoot.PushAsync(page);
-    }
-
     internal async Task GoBackAsync()
     {
-        await window.NavRoot.PopAsync();
+        await Window!.NavRoot.PopAsync();
     }
 }

src/PostIt/PostIt/Helpers/ServiceCollectionHelpers.cs

@@ -0,0 +1,77 @@
+using System;
+using Microsoft.Extensions.DependencyInjection;
+using PostIt.Services;
+using PostIt.ViewModels;
+using PostIt.Views;
+using Yavsc.Api.Client;
+
+namespace PostIt.Helpers;
+
+public static class ServiceCollectionHelpers
+{
+    public static IServiceProvider BuildServices(this ServiceCollection services)
+    {
+        var settings = new Settings();
+        settings.Load();
+
+        var tokenStore = new TokenStore(System.IO.Path.Combine(
+            System.Environment.GetFolderPath(System.Environment.SpecialFolder.ApplicationData),
+            "PostIt", "tokens.json"));
+
+        var api = new YavscApiClient(settings, tokenStore);
+        var client = new BlogApiClient(api, settings.BlogsApiUrl);
+        var circleClient = new CircleApiClient(api, settings.BlogsApiUrl);
+        var blogAclClient = new BlogAclApiClient(api, settings.BlogsApiUrl);
+        var userSearchClient = new UserSearchClient(api, settings.BlogsApiUrl);
+        var contactService = new ContactService();
+        var userDirectory = new UserDirectory(userSearchClient);
+
+        // Vues
+        services.AddTransient<MainPage>();
+        // SettingsPage is a singleton: there must be one and only one
+        // instance of the settings UI for the lifetime of the app.
+        // This guarantees that (a) the bindings always reflect the
+        // current in-memory Settings state, (b) the page already has
+        // its DataContext wired up at composition-root time (see
+        // below), and (c) PushPageAsync's anti-empilement guard sees
+        // the same instance across pushes, so a second Settings tap
+        // is a no-op rather than re-pushing the page. Transient would
+        // let the user accumulate stale SettingsPage instances on
+        // the navigation stack, each bound to a fresh
+        // SettingsViewModel and missing any in-flight edits.
+        services.AddSingleton<SettingsPage>();
+        services.AddTransient<HomePage>();
+        services.AddTransient<SignaturePage>();
+        services.AddTransient<CirclesPage>();
+        // Dialogs (modal-light pages): the ViewLocator resolves
+        // them when a caller pushes a PostAclDialogViewModel or
+        // AddCircleMemberDialogViewModel via App.PushPageAsync.
+        // App.PushPageAsync overwrites the page's DataContext with
+        // the caller-built VM, so the parameterless ctor is enough
+        // here — the parametrised ctors stay for direct test wiring.
+        services.AddTransient<PostAclDialog>();
+        services.AddTransient<AddCircleMemberDialog>();
+        // ViewModels
+        services.AddSingleton(settings);
+        services.AddSingleton<YavscApiClient>(api);
+        services.AddSingleton(client);
+        services.AddSingleton(circleClient);
+        services.AddSingleton(blogAclClient);
+        services.AddSingleton(userSearchClient);
+        services.AddSingleton<IContactService>(contactService);
+        services.AddSingleton<IUserDirectory>(userDirectory);
+        services.AddTransient<MainViewModel>();
+        services.AddTransient<HomePageViewModel>();
+        services.AddTransient<SignaturePageViewModel>();
+        services.AddTransient<CirclesPageViewModel>();
+
+        // Persistent session banner: one instance for the lifetime of
+        // the app so the same VM survives page navigation.
+        var sessionStatus = new SessionStatusViewModel { Api = api };
+        sessionStatus.Refresh();
+        services.AddSingleton(sessionStatus);
+        services.AddTransient<SessionStatusBanner>();
+
+        return services.BuildServiceProvider();
+    }
+}

src/PostIt/PostIt/Helpers/ViewModelBaseHelpers.cs

@@ -0,0 +1,50 @@
+using System;
+using System.Linq;
+using System.Threading.Tasks;
+using Avalonia.Controls;
+using PostIt.ViewModels;
+
+namespace PostIt.Helpers;
+
+public static class ViewModelBaseHelpers
+{
+    public static async Task PushPageAsync(this App app, ViewModelBase vm)
+    {
+        if (app.Window is null)
+        {
+            throw new InvalidOperationException("MainWindow is not initialized yet.");
+        }
+
+        var template = app.DataTemplates.FirstOrDefault(t => t.Match(vm));
+        if (template is null)
+        {
+            throw new InvalidOperationException($"No IDataTemplate found for {vm.GetType().Name}.");
+        }
+
+        var view = template.Build(vm);
+        if (view is null)
+        {
+            throw new InvalidOperationException(
+                $"Template for {vm.GetType().Name} returned <null>.");
+        }
+
+        var page = view as Page;
+        if (page is null)
+        {
+            // NavigationPage expects Page instances. Wrap any fallback control
+            // (e.g. ViewLocator error TextBlock) into a ContentPage so it can render.
+            page = new ContentPage { Content = view };
+        }
+
+        page.DataContext = vm;
+
+        // Avoid stacking the same singleton page twice (e.g. SettingsPage).
+        var stack = app.Window.NavRoot.NavigationStack;
+        if (stack.Count > 0 && ReferenceEquals(stack[stack.Count - 1], page))
+        {
+            return;
+        }
+
+        await app.Window.NavRoot.PushAsync(page);
+    }
+}

src/PostIt/PostIt/PostIt.csproj

@@ -1,32 +1,14 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <TargetFramework>net10.0</TargetFramework>
     <Nullable>enable</Nullable>
     <LangVersion>latest</LangVersion>
-    <AvaloniaUseCompiledBindingsByDefault>true</AvaloniaUseCompiledBindingsByDefault>
-    <AssemblyVersion>1.1.0.0</AssemblyVersion>
-    <FileVersion>1.1.0.0</FileVersion>
-    <InformationalVersion>1.1.0-beta.1+1.Branch.release-1.0.8-rc1.Sha.1167169aa89e1bf25290e9a152d27b357a500ab3</InformationalVersion>
-    <Version>1.1.0-beta.1</Version>
   </PropertyGroup>
+
   <ItemGroup>
     <AvaloniaResource Include="Assets\**" />
   </ItemGroup>
-  <ItemGroup>
-    <PackageReference Include="Avalonia" />
-    <PackageReference Include="Avalonia.Themes.Fluent" />
-    <PackageReference Include="Avalonia.Fonts.Inter" />
-    <PackageReference Include="Avalonia.AvaloniaEdit" />
-    <PackageReference Include="AvaloniaUI.DiagnosticsSupport">
-      <IncludeAssets Condition="'$(Configuration)' != 'Debug'">None</IncludeAssets>
-      <PrivateAssets Condition="'$(Configuration)' != 'Debug'">All</PrivateAssets>
-    </PackageReference>
-    <PackageReference Include="CommunityToolkit.Mvvm" />
-    <PackageReference Include="IdentityModel.OidcClient" />
-    <PackageReference Include="Microsoft.Extensions.DependencyInjection" />
-    <ProjectReference Include="../../Yavsc.Abstract/Yavsc.Abstract.csproj" />
-    <ProjectReference Include="../../Yavsc.Api.Client/Yavsc.Api.Client.csproj" />
-  </ItemGroup>
+
   <ItemGroup>
     <Content Include="postit-settings.json">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
@@ -38,6 +20,21 @@
     </EmbeddedResource>
   </ItemGroup>
   <ItemGroup>
-    <PackageReference Include="GitVersion.MsBuild" />
+    <PackageReference Include="Avalonia" />
+    <PackageReference Include="Avalonia.Themes.Fluent" />
+    <PackageReference Include="Avalonia.Fonts.Inter" />
+    <PackageReference Include="AvaloniaUI.DiagnosticsSupport">
+      <IncludeAssets Condition="'$(Configuration)' != 'Debug'">None</IncludeAssets>
+      <PrivateAssets Condition="'$(Configuration)' != 'Debug'">All</PrivateAssets>
+    </PackageReference>
+    <PackageReference Include="CommunityToolkit.Mvvm" />
+    <PackageReference Include="Avalonia.AvaloniaEdit" />
+    <PackageReference Include="IdentityModel.OidcClient" />
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="../../Yavsc.Abstract/Yavsc.Abstract.csproj" />
+    <ProjectReference Include="../../Yavsc.Api.Client/Yavsc.Api.Client.csproj" />
   </ItemGroup>
 </Project>

src/PostIt/PostIt/Settings/AuthenticationSettings.cs

@@ -21,6 +21,9 @@ public partial class AuthenticationSettings : ObservableObject
     public static string DefaultAuthority { get; internal set; } = "https://yavsc.pschneider.fr";
 
     public static string DefaultClientId { get; internal set; } = "postit";
+
+    public static string[] DefaultScopes { get; set; } = { "blogs"} ;
+
     [ObservableProperty]
     public partial string Authority { get; set; }
 

src/PostIt/PostIt/ViewLocator.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Diagnostics.CodeAnalysis;
 using Avalonia.Controls;
 using Avalonia.Controls.Templates;
 using Microsoft.Extensions.DependencyInjection;
@@ -10,7 +11,9 @@ namespace PostIt;
 /// <summary>
 /// Given a view model, returns the corresponding view if possible.
 /// </summary>
-
+[RequiresUnreferencedCode(
+    "Default implementation of ViewLocator involves reflection which may be trimmed away.",
+    Url = "https://docs.avaloniaui.net/docs/concepts/view-locator")]
 public class ViewLocator : IDataTemplate
 {
     private readonly IServiceProvider _services;
@@ -32,11 +35,12 @@ public class ViewLocator : IDataTemplate
         }
     }
 
+
     private Control BuildCore(object? data)
     {
         return data switch
         {
-            MainPageViewModel => _services.GetRequiredService<MainPage>(),
+            MainViewModel => _services.GetRequiredService<MainPage>(),
             Settings => _services.GetRequiredService<SettingsPage>(),
             HomePageViewModel => _services.GetRequiredService<HomePage>(),
             SignaturePageViewModel => _services.GetRequiredService<SignaturePage>(),

src/PostIt/PostIt/ViewModels/CirclesPageViewModel.cs

@@ -5,6 +5,7 @@ using Avalonia;
 using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Input;
 using Microsoft.Extensions.DependencyInjection;
+using PostIt.Helpers;
 using PostIt.Services;
 using Yavsc.Api.Client;
 using Yavsc.Api.Client.Dtos;

src/PostIt/PostIt/ViewModels/MainViewModel.cs

@@ -8,10 +8,11 @@ using CommunityToolkit.Mvvm.Input;
 using Microsoft.Extensions.DependencyInjection;
 using Yavsc.Blogspot;
 using Yavsc.Api.Client;
+using PostIt.Helpers;
 
 namespace PostIt.ViewModels;
 
-public partial class MainPageViewModel : ViewModelBase
+public partial class MainViewModel : ViewModelBase
 {
     /// <summary>Window/tab title. Cosmetic — bound by
     /// <c>MainPage.axaml</c> if at all. Not the post title.</summary>
@@ -120,10 +121,10 @@ public partial class MainPageViewModel : ViewModelBase
     }
 
 
-    public MainPageViewModel()
+    public MainViewModel()
     {
-        Init(null);
         SettingsModel = new Settings();
+        Init(SettingsModel);
         BlogClient = null;
     }
 
@@ -135,6 +136,11 @@ public partial class MainPageViewModel : ViewModelBase
         SelectedPost = null;
         IsBusy = false;
         StatusMessage = "Ready";
+        Settings = settings ?? new Settings();
+        WindowTitle = "PostIt";
+        DraftTitle = string.Empty;
+        DraftArticle = string.Empty;
+        DraftIsPublished = false;
         // Production path: DI injects the canonical Settings singleton
         // and we use it as-is. Test path: tests call this constructor
         // without a Settings argument; we fall back to a fresh
@@ -145,11 +151,7 @@ public partial class MainPageViewModel : ViewModelBase
         // sink; that crash is fixed in Settings.OnPropertyChanged
         // (thread-safe dispatcher marshalling) so the duplicate
         // instance is now merely wasteful, not dangerous.
-        Settings = settings ?? new Settings();
-        WindowTitle = "PostIt";
-        DraftTitle = string.Empty;
-        DraftArticle = string.Empty;
-        DraftIsPublished = false;
+
     }
 
     /// <summary>Save is enabled as soon as the user has typed
@@ -169,12 +171,11 @@ public partial class MainPageViewModel : ViewModelBase
     /// <see cref="BlogApiClient"/>. Production code uses the
     /// (Settings, BlogApiClient) overload below.
     /// </summary>
-    public MainPageViewModel(BlogApiClient blogClient, Settings? settings = null, IServiceProvider? services = null)
+    public MainViewModel(BlogApiClient blogClient, Settings? settings = null, IServiceProvider? services = null)
     {
         SettingsModel = new Settings();
         BlogClient = blogClient ?? throw new ArgumentNullException(nameof(blogClient)); ;
         Services = services;
-
         Init(settings);
     }
 
@@ -210,7 +211,7 @@ public partial class MainPageViewModel : ViewModelBase
     {
         await ExecuteAsync(async () =>
         {
-            var posts = await BlogClient.GetPostsAsync();
+            var posts = await BlogClient!.GetPostsAsync();
             Posts.Clear();
             foreach (var post in posts.OrderByDescending(p => p.DateModified))
             {
@@ -259,7 +260,7 @@ public partial class MainPageViewModel : ViewModelBase
                     DateCreated = DateTime.UtcNow,
                     DateModified = DateTime.UtcNow,
                 };
-                var created = await BlogClient.CreatePostAsync(draft);
+                var created = await BlogClient!.CreatePostAsync(draft);
                 if (created is not null)
                 {
                     SelectedPost = created;
@@ -278,7 +279,7 @@ public partial class MainPageViewModel : ViewModelBase
                     DateCreated = SelectedPost.DateCreated,
                     DateModified = DateTime.UtcNow,
                 };
-                await BlogClient.UpdatePostAsync(SelectedPost.Id, update);
+                await BlogClient!.UpdatePostAsync(SelectedPost.Id, update);
                 StatusMessage = $"Saved post {SelectedPost.Id}.";
             }
 
@@ -297,7 +298,7 @@ public partial class MainPageViewModel : ViewModelBase
 
         await ExecuteAsync(async () =>
         {
-            await BlogClient.DeletePostAsync(SelectedPost.Id);
+            await BlogClient!.DeletePostAsync(SelectedPost.Id);
             StatusMessage = $"Deleted post {SelectedPost.Id}.";
             SelectedPost = null;
             await RefreshPostsAsync();
@@ -331,7 +332,7 @@ public partial class MainPageViewModel : ViewModelBase
         await ExecuteAsync(async () =>
         {
             var desired = !DraftIsPublished;
-            await BlogClient.SetPublishAsync(SelectedPost.Id, desired);
+            await BlogClient!.SetPublishAsync(SelectedPost.Id, desired);
             DraftIsPublished = desired;
             // Mirror into the selected post so a subsequent
             // RefreshPostsAsync() doesn't blow away the
@@ -372,7 +373,7 @@ public partial class MainPageViewModel : ViewModelBase
 
     private async Task RefreshPostsAsync()
     {
-        var posts = await BlogClient.GetPostsAsync();
+        var posts = await BlogClient!.GetPostsAsync();
         Posts.Clear();
         foreach (var post in posts.OrderByDescending(p => p.DateModified))
         {

src/PostIt/PostIt/ViewModels/SessionStatusViewModel.cs

@@ -3,6 +3,7 @@ using System.Threading.Tasks;
 using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Input;
 using Microsoft.Extensions.DependencyInjection;
+using PostIt.Helpers;
 using PostIt.Services;
 
 namespace PostIt.ViewModels;
@@ -139,7 +140,7 @@ public partial class SessionStatusViewModel : ViewModelBase
     internal async Task OpenSettings()
     {
         var app = (App)App.Current!;
-        await app.PushPageAsync(app.ServiceProvider.GetRequiredService<Settings>()).ConfigureAwait(true);
+        await app.PushPageAsync(app.ServiceProvider!.GetRequiredService<Settings>()).ConfigureAwait(true);
     }
 
 }

src/PostIt/PostIt/ViewModels/Settings.cs

@@ -47,40 +47,7 @@ public partial class Settings : ViewModelBase
     /// </summary>
     private static Settings? s_current;
 
-    /// <summary>
-    /// Wire the canonical Settings instance to a DI container. Called
-    /// exactly once from <c>App.axaml.cs</c> after the singleton has
-    /// been registered. Subsequent calls are no-ops: the DI container
-    /// owns the instance lifetime and we don't want a stray
-    /// <c>BindToServiceProvider</c> in a test fixture to silently
-    /// rebind the production instance.
-    /// </summary>
-    public static void BindToServiceProvider(IServiceProvider services)
-    {
-        if (services is null) throw new ArgumentNullException(nameof(services));
-        Interlocked.CompareExchange(ref s_current,
-            services.GetService<Settings>() ?? throw new InvalidOperationException(
-                "Settings is not registered in the DI container."),
-            null);
-    }
    
-    /// <summary>
-    /// Returns the canonical Settings instance previously bound through
-    /// <see cref="BindToServiceProvider"/>, or <c>null</c> when called
-    /// outside a running Avalonia application (tests, CLI tools).
-    /// </summary>
-    public static Settings? GetCurrent() => Volatile.Read(ref s_current);
-
-    /// <summary>
-    /// Resolve the canonical Settings instance or throw. Use this in
-    /// production code paths that must not silently fall back to a
-    /// freshly-constructed <see cref="Settings"/> (which used to be
-    /// the root cause of the postit://callback crash: two Settings
-    /// instances racing on PropertyChanged from different threads).
-    /// </summary>
-    public static Settings RequireCurrent() =>
-        GetCurrent() ?? throw new InvalidOperationException(
-            "Settings.Current is not bound. Call App.OnFrameworkInitializationCompleted first.");
 
     [ObservableProperty]
     public partial AuthenticationSettings Authentication { get; set; } = new();
@@ -99,7 +66,7 @@ public partial class Settings : ViewModelBase
     /// setters above all funnel through here, and we flip
     /// <see cref="IsDirty"/> in lock-step. Sub-property mutations
     /// (e.g. <c>Authentication.Authority</c>) are caught by the
-    /// subscription wired up in <see cref="OnAuthenticationChanged"/>
+    /// subscription wired up in 
     /// below. <see cref="ApplyJson"/> disables the flag during bulk
     /// hydration so the disk load itself does not count as a user
     /// edit.
@@ -350,15 +317,14 @@ public partial class Settings : ViewModelBase
             var settings = JsonSerializer.Deserialize<Settings>(json);
             if (settings is null)
             {
-                Console.Error.WriteLine($"🩎 Settings payload is invalid (source: {source}).");
-                return;
+                UseDefaultSettings();
             }
             // Apply under the gate so concurrent Load() callers cannot
             // see half the new values / half the old ones. The actual
             // PropertyChanged fan-out is handled by [ObservableProperty]'s
             // setters which we route through SetProperty → OnPropertyChanged
             // → our overridden dispatcher-safe marshaller below.
-            lock (_mutationGate)
+            else lock (_mutationGate)
             {
                 this.Authentication = settings.Authentication;
                 this.DarkMode = settings.DarkMode;
@@ -371,6 +337,11 @@ public partial class Settings : ViewModelBase
                      AuthenticationSettings.DefaultClientId : settings.Authentication.ClientId;
                     this.Authentication.RedirectUri = string.IsNullOrWhiteSpace(settings.Authentication.RedirectUri) ?
                      AuthenticationSettings.DefaultDesktopRedirectUri : settings.Authentication.RedirectUri;
+                    if (settings.Authentication.Scopes is null || settings.Authentication.Scopes.Length == 0)
+                    {
+                        settings.Authentication.Scopes = AuthenticationSettings.DefaultScopes;
+                    }
+                    else
                     this.Authentication.Scopes = settings.Authentication.Scopes;
                 }
             }
@@ -400,6 +371,18 @@ public partial class Settings : ViewModelBase
         }
     }
 
+    private void UseDefaultSettings()
+    {
+        this.Authentication = new AuthenticationSettings
+        {
+            Authority = AuthenticationSettings.DefaultAuthority,
+            ClientId = AuthenticationSettings.DefaultClientId,
+            RedirectUri = AuthenticationSettings.DefaultDesktopRedirectUri,
+            Scopes = AuthenticationSettings.DefaultScopes
+        };
+        this.DarkMode = false;
+    }
+
     /// <summary>
     /// Persist the current in-memory state to
     /// <c>~/.config/PostIt/postit-settings.json</c> (Linux) /

src/PostIt/PostIt/ViewModels/ViewModelBase.cs

@@ -4,7 +4,6 @@ namespace PostIt.ViewModels;
 
 public abstract partial class ViewModelBase : ObservableObject
 {
-
      /// <summary>
     /// Gets if the user can navigate to the next page
     /// </summary>

src/PostIt/PostIt/Views/MainPage.axaml

@@ -8,11 +8,11 @@
              xmlns:AvaloniaEdit="clr-namespace:AvaloniaEdit;assembly=AvaloniaEdit"
              mc:Ignorable="d"
              x:Class="PostIt.Views.MainPage"
-             x:DataType="vm:MainPageViewModel"
+             x:DataType="vm:MainViewModel"
              HorizontalAlignment="Stretch"
              VerticalAlignment="Stretch">
     <Design.DataContext>
-        <vm:MainPageViewModel />
+        <vm:MainViewModel />
     </Design.DataContext>
 
     <Grid Margin="12" RowSpacing="12"

src/PostIt/PostIt/Views/MainWindow.axaml

@@ -1,27 +1,17 @@
 <Window xmlns="https://github.com/avaloniaui"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
         xmlns:vm="using:PostIt.ViewModels"
+        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
         xmlns:views="using:PostIt.Views"
-        x:DataType="vm:MainPageViewModel"
+        mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
         x:Class="PostIt.Views.MainWindow"
-        >
+        Icon="/Assets/avalonia-logo.ico"
+        Title="PostIt" >
 
-    <!--
-        Root layout: persistent session banner on top, navigation
-        surface below. The banner is the single source of truth for
-        "Connecté / Déconnecté" and the logout button — visible on
-        every page (HomePage, MainPage) so the user never has to dig
-        through a menu to find their session state.
-
-        The navigation stack is built programmatically in
-        App.OnFrameworkInitializationCompleted: HomePage is the
-        root, MainPage is pushed on top when the silent refresh
-        succeeds at boot or after a fresh login from HomePage.
-    -->
         <DockPanel LastChildFill="True">
         <views:SessionStatusBanner x:Name="SessionBanner"
                                    DockPanel.Dock="Bottom"/>
         <NavigationPage x:Name="NavRoot"/>
     </DockPanel>
-
 </Window>