Gestion des fichiers utilisateur et pièces jointes (demande/devis)

Espace de stockage personnel géré depuis PostIt, avec attachement par
référence (sans duplication) des fichiers à la demande du client
(NominativeServiceCommand) et au devis du fournisseur (Estimate).

Backend:
- UploadedFile.OwnerId (FK ApplicationUser, nullable) ; les téléversements
  vers api/v1/fs créent/mettent à jour une ligne propriétaire.
- Tables de jointure EstimateAttachedFile et QueryAttachedFile (PK composite),
  migration UserFileAttachments.
- EstimateApiController: GET/POST/DELETE estimate/{id}/attachments
  (fournisseur uniquement, fichier devant appartenir au caller).
- FrontOfficeApiController: GET/POST/DELETE front/query/{id}/attachments
  (client uniquement).
- FileSystemApiController: GET fs/file/{fileId} sert les octets depuis le
  host Blogs (autorisation propriétaire ou partie au devis/demande via DB
  partagée) — le host API ne gère que les métadonnées, contrainte des
  conteneurs docker à disques distincts.

Client .NET:
- UserFilesApiClient (list/upload/delete/download) pointant vers BlogsApiUrl.
- DTOs UserDirectoryDto/FileEntryDto/AttachmentDto/FileReceivedDto/UploadFile.
- Méthodes d'attachement sur EstimateApiClient et FrontOfficeApiClient.

PostIt (Avalonia):
- Page « Mes fichiers » (naviguer/téléverser/télécharger/supprimer), servant
  aussi de sélecteur pour l'attachement.
- Section pièces jointes dans l'édition du devis (fournisseur) et le détail
  de la demande (client), avec ajout depuis My Files, détachement,
  téléchargement.
- Enregistrement DI + mapping ViewLocator + bouton d'accès.

Tests:
- EstimateEditionPageViewModelTests mis à jour (nouveau ctor fsClient,
  historique d'appels du stub pour les assertions post-envoi).

Nommage HTTP/méthodes en anglais, documentation en français.

Co-Authored-By: Claude Code <noreply@anthropic.com>

src/PostIt/PostIt.Tests/EstimateEditionPageViewModelTests.cs

@@ -22,7 +22,8 @@ public class EstimateEditionPageViewModelTests
     private static EstimateEditionPageViewModel CreateViewModel(StubEstimateApi api, BillingQuerySummaryDto? query = null)
     {
         var client = new EstimateApiClient(api, "https://business.example/api/v1/");
-        return new EstimateEditionPageViewModel(query ?? SampleQuery(), client);
+        var fsClient = new UserFilesApiClient(api, "https://blogs.example/api/v1/");
+        return new EstimateEditionPageViewModel(query ?? SampleQuery(), client, fsClient);
     }
 
     [Fact]
@@ -143,10 +144,8 @@ public class EstimateEditionPageViewModelTests
 
         await vm.SendCommand.ExecuteAsync(null);
 
-        Assert.Equal("https://business.example/api/v1/estimate", api.LastPath);
-        Assert.Equal(HttpMethod.Post, api.LastMethod);
-
-        var payload = Assert.IsType<EstimateDto>(api.LastBody);
+        var postCall = Assert.Single(api.Calls, c => c.Method == HttpMethod.Post && c.Path == "https://business.example/api/v1/estimate");
+        var payload = Assert.IsType<EstimateDto>(postCall.Body);
         Assert.Equal(42, payload.CommandId);
         Assert.Equal("cli-1", payload.ClientId);
         Assert.Equal("Brush", payload.CommandType);
@@ -216,7 +215,8 @@ public class EstimateEditionPageViewModelTests
 
         await vm.SendCommand.ExecuteAsync(null);
 
-        var payload = Assert.IsType<EstimateDto>(api.LastBody);
+        var postCall = Assert.Single(api.Calls, c => c.Method == HttpMethod.Post && c.Path == "https://business.example/api/v1/estimate");
+        var payload = Assert.IsType<EstimateDto>(postCall.Body);
         Assert.Equal(2, payload.Bill.Count);
         Assert.Equal(-5m, payload.Bill[1].UnitaryCost);
         Assert.True(vm.HasSent);
@@ -230,11 +230,20 @@ public class EstimateEditionPageViewModelTests
         public object? LastBody { get; private set; }
         public Exception? Failure { get; init; }
 
-        public Task<T> CallAsync<T>(HttpMethod method, string path, object? body = null, CancellationToken ct = default)
+        /// <summary>Historique complet des appels (le plus récent en dernier).</summary>
+        public List<(HttpMethod Method, string Path, object? Body)> Calls { get; } = new();
+
+        private void Record(HttpMethod method, string path, object? body)
         {
             LastMethod = method;
             LastPath = path;
             LastBody = body;
+            Calls.Add((method, path, body));
+        }
+
+        public Task<T> CallAsync<T>(HttpMethod method, string path, object? body = null, CancellationToken ct = default)
+        {
+            Record(method, path, body);
 
             if (Failure is not null)
             {
@@ -253,9 +262,7 @@ public class EstimateEditionPageViewModelTests
 
         public Task CallAsync(HttpMethod method, string path, object? body = null, CancellationToken ct = default)
         {
-            LastMethod = method;
-            LastPath = path;
-            LastBody = body;
+            Record(method, path, body);
             return Task.CompletedTask;
         }
 
@@ -265,6 +272,12 @@ public class EstimateEditionPageViewModelTests
         public Task CallAsync(HttpMethod method, string path, Func<HttpContent> contentFactory, CancellationToken ct = default)
             => CallAsync(method, path, (object?)null, ct);
 
+        public Task<byte[]> DownloadAsync(HttpMethod method, string path, CancellationToken ct = default)
+        {
+            Record(method, path, null);
+            return Task.FromResult(Array.Empty<byte>());
+        }
+
         public ValueTask DisposeAsync() => ValueTask.CompletedTask;
     }
 }

src/PostIt/PostIt/Helpers/ServiceCollectionHelpers.cs

@@ -22,6 +22,7 @@ public static class ServiceCollectionHelpers
 
         var api = new YavscApiClient(settings, tokenStore);
         var client = new BlogApiClient(api, settings.BlogsApiUrl);
+        var userFilesClient = new UserFilesApiClient(api, settings.BlogsApiUrl);
         var circleClient = new CircleApiClient(api, settings.BlogsApiUrl);
         var blogAclClient = new BlogAclApiClient(api, settings.BlogsApiUrl);
         var userSearchClient = new UserSearchClient(api, settings.BlogsApiUrl);
@@ -65,6 +66,7 @@ public static class ServiceCollectionHelpers
         services.AddTransient<EstimateEditionPage>();
         services.AddTransient<EstimateListPage>();
         services.AddTransient<EstimateValidationPage>();
+        services.AddTransient<MyFilesPage>();
 
         // ViewModels
         services.AddSingleton(settings);
@@ -77,6 +79,7 @@ public static class ServiceCollectionHelpers
         services.AddSingleton(billingClient);
         services.AddSingleton(estimateClient);
         services.AddSingleton(frontClient);
+        services.AddSingleton(userFilesClient);
         services.AddSingleton<IReverseGeocodingService>(reverseGeocoding);
         services.AddSingleton<IUserDirectory>(userDirectory);
         services.AddSingleton<HomePageViewModel>();

src/PostIt/PostIt/ViewLocator.cs

@@ -56,6 +56,7 @@ public class ViewLocator : IDataTemplate
             EstimateEditionPageViewModel => services.GetRequiredService<EstimateEditionPage>(),
             EstimateListPageViewModel => services.GetRequiredService<EstimateListPage>(),
             EstimateValidationPageViewModel => services.GetRequiredService<EstimateValidationPage>(),
+            MyFilesViewModel => services.GetRequiredService<MyFilesPage>(),
             null => new TextBlock { Text = "No view for <null>" },
             _ => new TextBlock { Text = $"No view for {data.GetType().Name}" }
         };

src/PostIt/PostIt/ViewModels/Activity/BillingQueriesPageViewModel.cs

@@ -132,14 +132,18 @@ public partial class BillingQueriesPageViewModel : ViewModelBase, IActionStatusV
         {
             var details = await _billingClient.GetQueryAsync(Form.ActionName, SelectedQuery.Id).ConfigureAwait(true);
             var frontClient = app.ServiceProvider?.GetRequiredService<FrontOfficeApiClient>();
+            var fsClient = app.ServiceProvider?.GetRequiredService<UserFilesApiClient>();
             var vm = new BillingQueryDetailsPageViewModel(
                 Activity,
                 Performer,
                 Form,
                 _billingClient,
                 frontClient,
+                fsClient,
                 details,
-                IsReadOnly);
+                IsReadOnly,
+                canAttach: !IsReadOnly);
+            await vm.InitializeAsync().ConfigureAwait(true);
             await app.PushPageAsync(vm).ConfigureAwait(true);
         }
         catch (HttpRequestException ex) when (ex.StatusCode is HttpStatusCode.Unauthorized or HttpStatusCode.Forbidden)

src/PostIt/PostIt/ViewModels/Activity/BillingQueryDetailsPageViewModel.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.ObjectModel;
 using System.Linq;
 using System.Threading.Tasks;
 using Avalonia;
@@ -15,8 +16,17 @@ public partial class BillingQueryDetailsPageViewModel : ViewModelBase, IActionSt
 {
     private readonly BillingApiClient _billingClient;
     private readonly FrontOfficeApiClient _frontClient;
+    private readonly UserFilesApiClient _fsClient;
     private readonly BillingQueryDetailsDto _details;
 
+    /// <summary>
+    /// Vrai lorsque l'utilisateur courant est le client de la demande
+    /// et peut y attacher/détacher des fichiers de son espace perso.
+    /// Le fournisseur consulte et télécharge les pièces mais n'attache
+    /// pas (il joint ses documents au devis, côté <c>EstimateEditionPage</c>).
+    /// </summary>
+    public bool CanAttach { get; }
+
     public ActivityInfo Activity { get; }
     public ActivityUserDisplayItem Performer { get; }
     public CommandFormSummary Form { get; }
@@ -52,6 +62,10 @@ public partial class BillingQueryDetailsPageViewModel : ViewModelBase, IActionSt
     [ObservableProperty]
     public partial StatusNotice ActionStatus { get; set; } = StatusNotice.Info("Pret.");
 
+    /// <summary>Pièces jointes rattachées à la demande (par référence).</summary>
+    [ObservableProperty]
+    public partial ObservableCollection<AttachmentDto> Attachments { get; set; } = new();
+
     public override bool CanNavigateNext
     {
         get => false;
@@ -70,20 +84,27 @@ public partial class BillingQueryDetailsPageViewModel : ViewModelBase, IActionSt
         CommandFormSummary form,
         BillingApiClient billingClient,
         FrontOfficeApiClient frontClient,
+        UserFilesApiClient fsClient,
         BillingQueryDetailsDto details,
-        bool isReadOnly)
+        bool isReadOnly,
+        bool canAttach)
     {
         Activity = activity ?? throw new ArgumentNullException(nameof(activity));
         Performer = performer ?? throw new ArgumentNullException(nameof(performer));
         Form = form ?? throw new ArgumentNullException(nameof(form));
         _billingClient = billingClient ?? throw new ArgumentNullException(nameof(billingClient));
         _frontClient = frontClient ?? throw new ArgumentNullException(nameof(frontClient));
+        _fsClient = fsClient ?? throw new ArgumentNullException(nameof(fsClient));
         _details = details ?? throw new ArgumentNullException(nameof(details));
         IsReadOnly = isReadOnly;
+        CanAttach = canAttach;
 
         this.SetInfoStatus("Details de commande charges.");
     }
 
+    /// <summary>Constructeur pour le designer Avalonia.</summary>
+    public BillingQueryDetailsPageViewModel() : this(null!, null!, null!, null!, null!, null!, null!, false, false) { }
+
     [RelayCommand]
     private async Task OpenEditorAsync()
     {
@@ -134,6 +155,110 @@ public partial class BillingQueryDetailsPageViewModel : ViewModelBase, IActionSt
         await app.GoBackAsync().ConfigureAwait(true);
     }
 
+    /// <summary>Charge les pièces jointes de la demande.</summary>
+    public async Task InitializeAsync()
+    {
+        await LoadQueryAttachmentsAsync().ConfigureAwait(true);
+    }
+
+    [RelayCommand]
+    private async Task LoadQueryAttachmentsAsync()
+    {
+        try
+        {
+            var list = await _frontClient
+                .GetQueryAttachmentsAsync(BillingCode, Id)
+                .ConfigureAwait(true);
+            Attachments.Clear();
+            if (list is not null)
+                foreach (var a in list) Attachments.Add(a);
+        }
+        catch (Exception ex)
+        {
+            // Non bloquant : les pièces jointes sont un complément.
+            this.SetWarningStatus($"Pièces jointes indisponibles : {ex.Message}");
+        }
+    }
+
+    /// <summary>
+    /// Ouvre la page « My Files » en mode sélecteur ; le fichier choisi
+    /// est rattaché à la demande par référence via
+    /// <c>POST front/query/{id}/attachments</c>. Réservé au client
+    /// (<see cref="CanAttach"/>).
+    /// </summary>
+    [RelayCommand]
+    private async Task AddQueryAttachmentAsync()
+    {
+        if (!CanAttach) return;
+
+        var app = (App?)Application.Current;
+        if (app is null)
+        {
+            throw new InvalidOperationException("Application PostIt indisponible.");
+        }
+
+        var billingCode = BillingCode;
+        var queryId = Id;
+        var picker = new MyFilesViewModel(_fsClient, async fileId =>
+        {
+            try
+            {
+                await _frontClient.AttachQueryFileAsync(billingCode, queryId, fileId).ConfigureAwait(true);
+                await LoadQueryAttachmentsAsync().ConfigureAwait(true);
+                this.SetInfoStatus("Pièce jointe ajoutée à la demande.");
+            }
+            catch (Exception ex)
+            {
+                this.SetErrorStatus($"Échec de l'attachement : {ex.Message}");
+            }
+        });
+        await picker.InitializeAsync().ConfigureAwait(true);
+        await app.PushPageAsync(picker).ConfigureAwait(true);
+    }
+
+    [RelayCommand]
+    private async Task DetachQueryFileAsync(AttachmentDto? attachment)
+    {
+        if (attachment is null || !CanAttach) return;
+        IsBusy = true;
+        try
+        {
+            await _frontClient.DetachQueryFileAsync(BillingCode, Id, attachment.FileId).ConfigureAwait(true);
+            Attachments.Remove(attachment);
+            this.SetInfoStatus("Pièce jointe détachée de la demande.");
+        }
+        catch (Exception ex)
+        {
+            this.SetErrorStatus($"Échec du détachement : {ex.Message}");
+        }
+        finally
+        {
+            IsBusy = false;
+        }
+    }
+
+    [RelayCommand]
+    private async Task DownloadQueryAttachmentAsync(AttachmentDto? attachment)
+    {
+        if (attachment is null) return;
+        IsBusy = true;
+        try
+        {
+            var bytes = await _fsClient.DownloadFileAsync(attachment.FileId).ConfigureAwait(true);
+            var name = System.IO.Path.GetFileName(attachment.Path ?? "file");
+            var saved = await FileSaveHelpers.SaveAsync(name, "bin", bytes).ConfigureAwait(true);
+            this.SetInfoStatus(saved ? "Fichier enregistré." : "Téléchargement annulé.");
+        }
+        catch (Exception ex)
+        {
+            this.SetErrorStatus($"Échec du téléchargement : {ex.Message}");
+        }
+        finally
+        {
+            IsBusy = false;
+        }
+    }
+
     /// <summary>
     /// Download the estimate linked to this command as a LaTeX source
     /// (<c>GET api/v1/front/query/{Id}/estimate.tex</c>). The estimate is

src/PostIt/PostIt/ViewModels/Activity/EstimateEditionPageViewModel.cs

@@ -25,6 +25,7 @@ namespace PostIt.ViewModels;
 public partial class EstimateEditionPageViewModel : ViewModelBase, IActionStatusViewModel
 {
     private readonly EstimateApiClient _estimateClient;
+    private readonly UserFilesApiClient _fsClient;
     private readonly BillingQuerySummaryDto _query;
 
     public long QueryId => _query.Id;
@@ -68,6 +69,14 @@ public partial class EstimateEditionPageViewModel : ViewModelBase, IActionStatus
     [ObservableProperty]
     public partial StatusNotice ActionStatus { get; set; } = StatusNotice.Info("Prêt.");
 
+    /// <summary>Identifiant du devis, renseigné après l'envoi.</summary>
+    [ObservableProperty, NotifyCanExecuteChangedFor(nameof(AddAttachmentCommand))]
+    public partial long? EstimateId { get; set; }
+
+    /// <summary>Pièces jointes rattachées au devis (par référence).</summary>
+    [ObservableProperty]
+    public partial ObservableCollection<AttachmentDto> Attachments { get; set; } = new();
+
     public decimal Total => Lines.Sum(line => line.LineTotal);
 
     public string TotalLabel => $"{Total:0.00} {Lines.FirstOrDefault()?.Currency ?? "EUR"}";
@@ -86,10 +95,14 @@ public partial class EstimateEditionPageViewModel : ViewModelBase, IActionStatus
         protected set { _ = value; }
     }
 
-    public EstimateEditionPageViewModel(BillingQuerySummaryDto query, EstimateApiClient estimateClient)
+    public EstimateEditionPageViewModel(
+        BillingQuerySummaryDto query,
+        EstimateApiClient estimateClient,
+        UserFilesApiClient fsClient)
     {
         _query = query ?? throw new ArgumentNullException(nameof(query));
         _estimateClient = estimateClient ?? throw new ArgumentNullException(nameof(estimateClient));
+        _fsClient = fsClient ?? throw new ArgumentNullException(nameof(fsClient));
 
         EstimateDescription = query.Description ?? string.Empty;
         Lines.CollectionChanged += OnLinesCollectionChanged;
@@ -98,6 +111,9 @@ public partial class EstimateEditionPageViewModel : ViewModelBase, IActionStatus
         this.SetInfoStatus("Complétez le devis puis envoyez-le. La demande associée sera validée.");
     }
 
+    /// <summary>Constructeur pour le designer Avalonia.</summary>
+    public EstimateEditionPageViewModel() : this(null!, null!, null!) { }
+
     [RelayCommand]
     private void AddLine()
     {
@@ -141,9 +157,11 @@ public partial class EstimateEditionPageViewModel : ViewModelBase, IActionStatus
             var created = await _estimateClient.CreateAsync(payload).ConfigureAwait(true);
 
             HasSent = true;
+            EstimateId = created.Id;
             OnPropertyChanged(nameof(SendLabel));
             this.SetInfoStatus(
                 $"Devis #{created.Id} envoyé ({created.Bill.Count} ligne(s)). La demande #{QueryId} est validée.");
+            await LoadAttachmentsAsync().ConfigureAwait(true);
         }
         catch (HttpRequestException ex) when (ex.StatusCode is HttpStatusCode.Unauthorized or HttpStatusCode.Forbidden)
         {
@@ -171,6 +189,106 @@ public partial class EstimateEditionPageViewModel : ViewModelBase, IActionStatus
         await app.GoBackAsync().ConfigureAwait(true);
     }
 
+    /// <summary>
+    /// Charge les pièces jointes rattachées au devis courant
+    /// (<c>GET estimate/{id}/attachments</c>).
+    /// </summary>
+    [RelayCommand]
+    private async Task LoadAttachmentsAsync()
+    {
+        if (EstimateId is null || _estimateClient is null) return;
+        try
+        {
+            var list = await _estimateClient.GetAttachmentsAsync(EstimateId.Value).ConfigureAwait(true);
+            Attachments.Clear();
+            if (list is not null)
+                foreach (var a in list) Attachments.Add(a);
+        }
+        catch (Exception ex)
+        {
+            this.SetWarningStatus($"Impossible de charger les pièces jointes : {ex.Message}");
+        }
+    }
+
+    private bool CanAddAttachment() => EstimateId is not null && !IsBusy;
+
+    /// <summary>
+    /// Ouvre la page « My Files » en mode sélecteur ; le fichier choisi
+    /// est rattaché au devis par référence via
+    /// <c>POST estimate/{id}/attachments</c>.
+    /// </summary>
+    [RelayCommand(CanExecute = nameof(CanAddAttachment))]
+    private async Task AddAttachmentAsync()
+    {
+        if (EstimateId is null) return;
+
+        var app = (App?)Application.Current;
+        if (app is null)
+        {
+            throw new InvalidOperationException("Application PostIt indisponible.");
+        }
+
+        var estimateId = EstimateId.Value;
+        var picker = new MyFilesViewModel(_fsClient, async fileId =>
+        {
+            try
+            {
+                await _estimateClient.AttachFileAsync(estimateId, fileId).ConfigureAwait(true);
+                await LoadAttachmentsAsync().ConfigureAwait(true);
+                this.SetInfoStatus("Pièce jointe ajoutée au devis.");
+            }
+            catch (Exception ex)
+            {
+                this.SetErrorStatus($"Échec de l'attachement : {ex.Message}");
+            }
+        });
+        await picker.InitializeAsync().ConfigureAwait(true);
+        await app.PushPageAsync(picker).ConfigureAwait(true);
+    }
+
+    [RelayCommand]
+    private async Task DetachFileAsync(AttachmentDto? attachment)
+    {
+        if (attachment is null || EstimateId is null) return;
+        IsBusy = true;
+        try
+        {
+            await _estimateClient.DetachFileAsync(EstimateId.Value, attachment.FileId).ConfigureAwait(true);
+            Attachments.Remove(attachment);
+            this.SetInfoStatus("Pièce jointe détachée du devis.");
+        }
+        catch (Exception ex)
+        {
+            this.SetErrorStatus($"Échec du détachement : {ex.Message}");
+        }
+        finally
+        {
+            IsBusy = false;
+        }
+    }
+
+    [RelayCommand]
+    private async Task DownloadAttachmentAsync(AttachmentDto? attachment)
+    {
+        if (attachment is null) return;
+        IsBusy = true;
+        try
+        {
+            var bytes = await _fsClient.DownloadFileAsync(attachment.FileId).ConfigureAwait(true);
+            var name = System.IO.Path.GetFileName(attachment.Path ?? "file");
+            var saved = await FileSaveHelpers.SaveAsync(name, "bin", bytes).ConfigureAwait(true);
+            this.SetInfoStatus(saved ? "Fichier enregistré." : "Téléchargement annulé.");
+        }
+        catch (Exception ex)
+        {
+            this.SetErrorStatus($"Échec du téléchargement : {ex.Message}");
+        }
+        finally
+        {
+            IsBusy = false;
+        }
+    }
+
     internal EstimateDto BuildPayload()
     {
         return new EstimateDto

src/PostIt/PostIt/ViewModels/Activity/ProviderOngoingRequestsPageViewModel.cs

@@ -155,6 +155,7 @@ public partial class ProviderOngoingRequestsPageViewModel : ViewModelBase, IActi
                 .ConfigureAwait(true);
             var (activity, performer, form) = BuildNavigationContext(SelectedQuery);
             var frontClient = app.ServiceProvider?.GetRequiredService<FrontOfficeApiClient>();
+            var fsClient = app.ServiceProvider?.GetRequiredService<UserFilesApiClient>();
 
             var vm = new BillingQueryDetailsPageViewModel(
                 activity,
@@ -162,9 +163,12 @@ public partial class ProviderOngoingRequestsPageViewModel : ViewModelBase, IActi
                 form,
                 _billingClient,
                 frontClient,
+                fsClient,
                 details,
-                isReadOnly: false);
+                isReadOnly: false,
+                canAttach: false);
 
+            await vm.InitializeAsync().ConfigureAwait(true);
             await app.PushPageAsync(vm).ConfigureAwait(true);
         }
         catch (Exception ex)
@@ -243,7 +247,13 @@ public partial class ProviderOngoingRequestsPageViewModel : ViewModelBase, IActi
             throw new InvalidOperationException("Application PostIt indisponible.");
         }
 
-        var vm = new EstimateEditionPageViewModel(SelectedQuery, _estimateClient);
+        var fsClient = app.ServiceProvider?.GetRequiredService<UserFilesApiClient>();
+        if (fsClient is null)
+        {
+            throw new InvalidOperationException("Client fichiers indisponible.");
+        }
+
+        var vm = new EstimateEditionPageViewModel(SelectedQuery, _estimateClient, fsClient);
         await app.PushPageAsync(vm).ConfigureAwait(true);
     }
 

src/PostIt/PostIt/ViewModels/Layout/HomePageViewModel.cs

@@ -35,12 +35,14 @@ public class HomePageViewModel : ViewModelBase
         OpenClientEstimates = new AsyncRelayCommand(() => OpenEstimateListAsync(EstimateListPerspective.Client));
         OpenProviderEstimates = new AsyncRelayCommand(() => OpenEstimateListAsync(EstimateListPerspective.Provider));
         OpenBlogs = new AsyncRelayCommand(App.PushBlogsPageAsync);
+        OpenMyFiles = new AsyncRelayCommand(OpenMyFilesAsync);
     }
     public IAsyncRelayCommand OpenBlogs { get; }
     public IAsyncRelayCommand OpenActivities { get; }
     public IAsyncRelayCommand OpenProviderRequests { get; }
     public IAsyncRelayCommand OpenClientEstimates { get; }
     public IAsyncRelayCommand OpenProviderEstimates { get; }
+    public IAsyncRelayCommand OpenMyFiles { get; }
 
     private async Task OpenActivitiesAsync()
     {
@@ -101,6 +103,29 @@ public class HomePageViewModel : ViewModelBase
         await app.PushPageAsync(vm);
     }
 
+    /// <summary>
+    /// Ouvre la page « Mes fichiers » (espace de stockage personnel),
+    /// servie par le host Blogs via <c>api/v1/fs</c>.
+    /// </summary>
+    private async Task OpenMyFilesAsync()
+    {
+        var app = (App?)Application.Current;
+        if (app is null)
+        {
+            throw new InvalidOperationException("Application PostIt indisponible.");
+        }
+
+        var fsClient = app.ServiceProvider?.GetRequiredService<Yavsc.Api.Client.UserFilesApiClient>();
+        if (fsClient is null)
+        {
+            throw new InvalidOperationException("Client fichiers indisponible.");
+        }
+
+        var vm = new MyFilesViewModel(fsClient);
+        await vm.InitializeAsync();
+        await app.PushPageAsync(vm);
+    }
+
     /// <summary>
     /// Avalonia designer constructor. Builds a self-contained VM
     /// with a freshly-constructed Settings so the XAML preview can

src/PostIt/PostIt/ViewModels/MyFiles/MyFilesViewModel.cs

@@ -0,0 +1,229 @@
+using System;
+using System.Collections.ObjectModel;
+using System.IO;
+using System.Linq;
+using System.Threading.Tasks;
+using Avalonia;
+using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Input;
+using PostIt.Helpers;
+using Yavsc.Api.Client;
+
+namespace PostIt.ViewModels;
+
+/// <summary>
+/// Gestion de l'espace de stockage personnel (« My Files ») :
+/// navigation dans l'arbre, téléversement, suppression, téléchargement.
+/// Sert aussi de **sélecteur** pour attacher un fichier à un devis
+/// (fournisseur) ou à une demande (client) par référence : lorsque
+/// <see cref="IsPickerMode"/> est vrai, la sélection d'un fichier invoque
+/// <see cref="_onFilePicked"/> avec l'identifiant <see cref="FileEntryDto.Id"/>
+/// puis revient à la page précédente.
+/// </summary>
+public partial class MyFilesViewModel : ViewModelBase, IActionStatusViewModel
+{
+    private readonly UserFilesApiClient _fs;
+    private readonly Action<long>? _onFilePicked;
+
+    /// <summary>
+    /// Sous-répertoire courant, relatif à la racine de l'espace perso
+    /// (chaîne vide à la racine). Servi tel quel à <c>GET/POST fs/{subdir}</c>.
+    /// </summary>
+    [ObservableProperty]
+    public partial string CurrentPath { get; set; } = string.Empty;
+
+    public string PathLabel => string.IsNullOrWhiteSpace(CurrentPath)
+        ? "Mes fichiers"
+        : $"Mes fichiers / {CurrentPath}";
+
+    public bool IsPickerMode => _onFilePicked is not null;
+
+    public bool CanGoUp => !string.IsNullOrWhiteSpace(CurrentPath);
+
+    [ObservableProperty]
+    public partial ObservableCollection<FileEntryDto> Files { get; set; } = new();
+
+    [ObservableProperty]
+    public partial ObservableCollection<DirEntryDto> SubDirectories { get; set; } = new();
+
+    [ObservableProperty]
+    public partial bool IsBusy { get; set; }
+
+    [ObservableProperty]
+    public partial string StatusMessage { get; set; } = "Prêt.";
+
+    [ObservableProperty]
+    public partial StatusNotice ActionStatus { get; set; } = StatusNotice.Info("Prêt.");
+
+    public override bool CanNavigateNext { get => false; protected set { _ = value; } }
+    public override bool CanNavigatePrevious { get => true; protected set { _ = value; } }
+
+    public MyFilesViewModel(UserFilesApiClient fs, Action<long>? onFilePicked = null)
+    {
+        _fs = fs ?? throw new ArgumentNullException(nameof(fs));
+        _onFilePicked = onFilePicked;
+    }
+
+    /// <summary>Constructeur pour le designer Avalonia.</summary>
+    public MyFilesViewModel() : this(null!) { }
+
+    public async Task InitializeAsync()
+    {
+        await RefreshAsync().ConfigureAwait(true);
+    }
+
+    [RelayCommand]
+    private async Task RefreshAsync()
+    {
+        IsBusy = true;
+        try
+        {
+            var dir = await _fs.ListAsync(CurrentPath).ConfigureAwait(true);
+            Files.Clear();
+            SubDirectories.Clear();
+            if (dir?.Files is not null)
+                foreach (var f in dir.Files) Files.Add(f);
+            if (dir?.SubDirectories is not null)
+                foreach (var d in dir.SubDirectories) SubDirectories.Add(d);
+            this.SetInfoStatus($"{Files.Count} fichier(s), {SubDirectories.Count} dossier(s).");
+        }
+        catch (Exception ex)
+        {
+            this.SetErrorStatus($"Erreur de listage : {ex.Message}");
+        }
+        finally
+        {
+            IsBusy = false;
+        }
+    }
+
+    [RelayCommand]
+    private async Task OpenDirAsync(DirEntryDto? dir)
+    {
+        if (dir is null) return;
+        CurrentPath = CombinePath(CurrentPath, dir.Name ?? string.Empty);
+        OnPropertyChanged(nameof(PathLabel));
+        OnPropertyChanged(nameof(CanGoUp));
+        await RefreshAsync().ConfigureAwait(true);
+    }
+
+    [RelayCommand]
+    private async Task UpAsync()
+    {
+        if (!CanGoUp) return;
+        CurrentPath = ParentPath(CurrentPath);
+        OnPropertyChanged(nameof(PathLabel));
+        OnPropertyChanged(nameof(CanGoUp));
+        await RefreshAsync().ConfigureAwait(true);
+    }
+
+    /// <summary>Téléversement déclenché par le code-behind (picker OS).</summary>
+    public async Task UploadAsync(System.Collections.Generic.IReadOnlyCollection<UploadFile> uploads)
+    {
+        if (uploads is null || uploads.Count == 0) return;
+        IsBusy = true;
+        try
+        {
+            var received = await _fs.UploadAsync(CurrentPath, uploads).ConfigureAwait(true);
+            this.SetInfoStatus($"{received.Count} fichier(s) téléversé(s).");
+            await RefreshAsync().ConfigureAwait(true);
+        }
+        catch (Exception ex)
+        {
+            this.SetErrorStatus($"Échec du téléversement : {ex.Message}");
+        }
+        finally
+        {
+            IsBusy = false;
+        }
+    }
+
+    [RelayCommand]
+    private async Task DeleteFileAsync(FileEntryDto? file)
+    {
+        if (file is null) return;
+        IsBusy = true;
+        try
+        {
+            await _fs.DeleteAsync(CombinePath(CurrentPath, file.Name ?? string.Empty)).ConfigureAwait(true);
+            this.SetInfoStatus($"Fichier supprimé.");
+            await RefreshAsync().ConfigureAwait(true);
+        }
+        catch (Exception ex)
+        {
+            this.SetErrorStatus($"Échec de la suppression : {ex.Message}");
+        }
+        finally
+        {
+            IsBusy = false;
+        }
+    }
+
+    [RelayCommand]
+    private async Task DownloadFileAsync(FileEntryDto? file)
+    {
+        if (file is null || file.Id is null) return;
+        IsBusy = true;
+        try
+        {
+            var bytes = await _fs.DownloadFileAsync(file.Id.Value).ConfigureAwait(true);
+            var saved = await FileSaveHelpers.SaveAsync(file.Name ?? "file", "bin", bytes).ConfigureAwait(true);
+            this.SetInfoStatus(saved ? "Fichier enregistré." : "Téléchargement annulé.");
+        }
+        catch (Exception ex)
+        {
+            this.SetErrorStatus($"Échec du téléchargement : {ex.Message}");
+        }
+        finally
+        {
+            IsBusy = false;
+        }
+    }
+
+    [RelayCommand]
+    private async Task PickFileAsync(FileEntryDto? file)
+    {
+        if (file is null || file.Id is null)
+        {
+            this.SetWarningStatus("Ce fichier n'est pas référencé (aucun id). Téléversez-le d'abord.");
+            return;
+        }
+
+        var callback = _onFilePicked;
+        if (callback is null)
+        {
+            // Mode gestion : le téléchargement est l'action par défaut.
+            await DownloadFileAsync(file).ConfigureAwait(true);
+            return;
+        }
+
+        callback(file.Id.Value);
+        await GoBackAsync().ConfigureAwait(true);
+    }
+
+    [RelayCommand]
+    private async Task BackAsync()
+    {
+        await GoBackAsync().ConfigureAwait(true);
+    }
+
+    private static async Task GoBackAsync()
+    {
+        var app = (App?)Application.Current;
+        if (app is null) throw new InvalidOperationException("Application PostIt indisponible.");
+        await app.GoBackAsync().ConfigureAwait(true);
+    }
+
+    private static string CombinePath(string current, string name)
+    {
+        if (string.IsNullOrWhiteSpace(current)) return name;
+        return $"{current}/{name}";
+    }
+
+    private static string ParentPath(string current)
+    {
+        if (string.IsNullOrWhiteSpace(current)) return string.Empty;
+        var idx = current.LastIndexOf('/');
+        return idx < 0 ? string.Empty : current[..idx];
+    }
+}

src/PostIt/PostIt/Views/Activity/BillingQueryDetailsPage.axaml

@@ -1,6 +1,7 @@
 <ContentPage xmlns="https://github.com/avaloniaui"
              xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
              xmlns:vm="using:PostIt.ViewModels"
+             xmlns:client="using:Yavsc.Api.Client"
              xmlns:postitControls="using:PostIt.Controls"
              x:Class="PostIt.Views.BillingQueryDetailsPage"
              x:DataType="vm:BillingQueryDetailsPageViewModel"
@@ -80,6 +81,53 @@
                     </Grid>
                 </Border>
 
+                <!-- Pièces jointes (par référence à l'espace perso du client) -->
+                <Border BorderThickness="1"
+                        BorderBrush="#22000000"
+                        CornerRadius="8"
+                        Padding="10">
+                    <StackPanel Spacing="8">
+                        <Grid ColumnDefinitions="*,Auto">
+                            <TextBlock Grid.Column="0"
+                                       Text="Pièces jointes"
+                                       FontWeight="SemiBold"
+                                       VerticalAlignment="Center" />
+                            <Button Grid.Column="1"
+                                    Content="Ajouter depuis My Files"
+                                    Command="{Binding AddQueryAttachmentCommand}"
+                                    IsVisible="{Binding CanAttach}" />
+                        </Grid>
+
+                        <ItemsControl ItemsSource="{Binding Attachments}">
+                            <ItemsControl.ItemTemplate>
+                                <DataTemplate x:DataType="client:AttachmentDto">
+                                    <Border BorderThickness="1"
+                                            BorderBrush="#11000000"
+                                            CornerRadius="6"
+                                            Padding="8"
+                                            Margin="0,0,0,6">
+                                        <Grid ColumnDefinitions="*,Auto,8,Auto">
+                                            <TextBlock Grid.Column="0"
+                                                       Text="{Binding Path}"
+                                                       VerticalAlignment="Center"
+                                                       TextTrimming="CharacterEllipsis" />
+                                            <Button Grid.Column="1"
+                                                    Content="Télécharger"
+                                                    Command="{Binding $parent[vm:BillingQueryDetailsPageViewModel].DownloadQueryAttachmentCommand}"
+                                                    CommandParameter="{Binding}" />
+                                            <Button Grid.Column="3"
+                                                    Content="Détacher"
+                                                    Command="{Binding $parent[vm:BillingQueryDetailsPageViewModel].DetachQueryFileCommand}"
+                                                    CommandParameter="{Binding}"
+                                                    IsVisible="{Binding $parent[vm:BillingQueryDetailsPageViewModel].CanAttach}" />
+                                        </Grid>
+                                    </Border>
+                                </DataTemplate>
+                            </ItemsControl.ItemTemplate>
+                        </ItemsControl>
+                    </StackPanel>
+                </Border>
+
                 <Expander Header="Metadonnees techniques"
                           IsExpanded="False">
                     <Border BorderThickness="1"

src/PostIt/PostIt/Views/Activity/EstimateEditionPage.axaml

@@ -1,6 +1,7 @@
 <ContentPage xmlns="https://github.com/avaloniaui"
              xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
              xmlns:vm="using:PostIt.ViewModels"
+             xmlns:client="using:Yavsc.Api.Client"
              xmlns:postitControls="using:PostIt.Controls"
              x:Class="PostIt.Views.EstimateEditionPage"
              x:DataType="vm:EstimateEditionPageViewModel"
@@ -133,6 +134,52 @@
                         </Grid>
                     </StackPanel>
                 </Border>
+
+                <!-- Pièces jointes (par référence à l'espace perso du fournisseur) -->
+                <Border BorderThickness="1"
+                        BorderBrush="#22000000"
+                        CornerRadius="8"
+                        Padding="10"
+                        IsVisible="{Binding HasSent}">
+                    <StackPanel Spacing="8">
+                        <Grid ColumnDefinitions="*,Auto">
+                            <TextBlock Grid.Column="0"
+                                       Text="Pièces jointes"
+                                       FontWeight="SemiBold"
+                                       VerticalAlignment="Center" />
+                            <Button Grid.Column="1"
+                                    Content="Ajouter depuis My Files"
+                                    Command="{Binding AddAttachmentCommand}" />
+                        </Grid>
+
+                        <ItemsControl ItemsSource="{Binding Attachments}">
+                            <ItemsControl.ItemTemplate>
+                                <DataTemplate x:DataType="client:AttachmentDto">
+                                    <Border BorderThickness="1"
+                                            BorderBrush="#11000000"
+                                            CornerRadius="6"
+                                            Padding="8"
+                                            Margin="0,0,0,6">
+                                        <Grid ColumnDefinitions="*,Auto,8,Auto,8,Auto">
+                                            <TextBlock Grid.Column="0"
+                                                       Text="{Binding Path}"
+                                                       VerticalAlignment="Center"
+                                                       TextTrimming="CharacterEllipsis" />
+                                            <Button Grid.Column="1"
+                                                    Content="Télécharger"
+                                                    Command="{Binding $parent[vm:EstimateEditionPageViewModel].DownloadAttachmentCommand}"
+                                                    CommandParameter="{Binding}" />
+                                            <Button Grid.Column="3"
+                                                    Content="Détacher"
+                                                    Command="{Binding $parent[vm:EstimateEditionPageViewModel].DetachFileCommand}"
+                                                    CommandParameter="{Binding}" />
+                                        </Grid>
+                                    </Border>
+                                </DataTemplate>
+                            </ItemsControl.ItemTemplate>
+                        </ItemsControl>
+                    </StackPanel>
+                </Border>
             </StackPanel>
         </ScrollViewer>
 

src/PostIt/PostIt/Views/Layout/HomePage.axaml

@@ -34,5 +34,9 @@
               Command="{Binding OpenProviderEstimates}"
               HorizontalAlignment="Center"
               IsEnabled="{Binding SessionStatus.IsLoggedIn}"/>
+          <Button Content="Mes fichiers"
+              Command="{Binding OpenMyFiles}"
+              HorizontalAlignment="Center"
+              IsEnabled="{Binding SessionStatus.IsLoggedIn}"/>
         </StackPanel>
 </ContentPage>

src/PostIt/PostIt/Views/MyFiles/MyFilesPage.axaml

@@ -0,0 +1,90 @@
+<ContentPage xmlns="https://github.com/avaloniaui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:vm="using:PostIt.ViewModels"
+             xmlns:client="using:Yavsc.Api.Client"
+             xmlns:postitControls="using:PostIt.Controls"
+             x:Class="PostIt.Views.MyFilesPage"
+             x:DataType="vm:MyFilesViewModel"
+             Header="Mes fichiers">
+    <Grid RowDefinitions="Auto,Auto,*,Auto" Margin="12">
+        <StackPanel Grid.Row="0" Spacing="3">
+            <TextBlock Text="{Binding PathLabel}"
+                       FontSize="20"
+                       FontWeight="Bold" />
+            <TextBlock Text="Espace de stockage personnel. Téléversez vos fichiers puis attachez-les à un devis ou une demande."
+                       Opacity="0.7"
+                       TextWrapping="Wrap" />
+        </StackPanel>
+
+        <Grid Grid.Row="1" ColumnDefinitions="Auto,8,Auto,8,*" Margin="0,10,0,8">
+            <Button Grid.Column="0"
+                    Content="Retour"
+                    Command="{Binding BackCommand}" />
+            <Button Grid.Column="2"
+                    Content="Remonter"
+                    Command="{Binding UpCommand}"
+                    IsEnabled="{Binding CanGoUp}" />
+            <Button Grid.Column="4"
+                    Content="Téléverser…"
+                    Click="Upload_Click"
+                    HorizontalAlignment="Right" />
+        </Grid>
+
+        <ScrollViewer Grid.Row="2">
+            <StackPanel Spacing="10">
+                <ItemsControl ItemsSource="{Binding SubDirectories}">
+                    <ItemsControl.ItemTemplate>
+                        <DataTemplate x:DataType="client:DirEntryDto">
+                            <Button Content="📁 {Binding Name}"
+                                    Command="{Binding $parent[vm:MyFilesViewModel].OpenDirCommand}"
+                                    CommandParameter="{Binding}"
+                                    HorizontalAlignment="Left"
+                                    Margin="0,0,0,4" />
+                        </DataTemplate>
+                    </ItemsControl.ItemTemplate>
+                </ItemsControl>
+
+                <ItemsControl ItemsSource="{Binding Files}">
+                    <ItemsControl.ItemTemplate>
+                        <DataTemplate x:DataType="client:FileEntryDto">
+                            <Border BorderThickness="1"
+                                    BorderBrush="#22000000"
+                                    CornerRadius="6"
+                                    Padding="8"
+                                    Margin="0,0,0,6">
+                                <Grid ColumnDefinitions="*,Auto,8,Auto,8,Auto">
+                                    <TextBlock Grid.Column="0"
+                                               Text="{Binding Name}"
+                                               VerticalAlignment="Center"
+                                               TextWrapping="NoWrap" />
+                                    <Button Grid.Column="1"
+                                            Content="Joindre"
+                                            Command="{Binding $parent[vm:MyFilesViewModel].PickFileCommand}"
+                                            CommandParameter="{Binding}"
+                                            IsVisible="{Binding $parent[vm:MyFilesViewModel].IsPickerMode}" />
+                                    <Button Grid.Column="3"
+                                            Content="Télécharger"
+                                            Command="{Binding $parent[vm:MyFilesViewModel].DownloadFileCommand}"
+                                            CommandParameter="{Binding}" />
+                                    <Button Grid.Column="5"
+                                            Content="Supprimer"
+                                            Command="{Binding $parent[vm:MyFilesViewModel].DeleteFileCommand}"
+                                            CommandParameter="{Binding}" />
+                                </Grid>
+                            </Border>
+                        </DataTemplate>
+                    </ItemsControl.ItemTemplate>
+                </ItemsControl>
+            </StackPanel>
+        </ScrollViewer>
+
+        <Grid Grid.Row="3" ColumnDefinitions="Auto,8,*,Auto" Margin="0,12,0,0">
+            <postitControls:StatusBar Grid.Column="0"
+                                       DataContext="{Binding ActionStatus}" />
+            <ProgressBar Grid.Column="3"
+                         Width="120"
+                         IsIndeterminate="True"
+                         IsVisible="{Binding IsBusy}" />
+        </Grid>
+    </Grid>
+</ContentPage>

src/PostIt/PostIt/Views/MyFiles/MyFilesPage.axaml.cs

@@ -0,0 +1,58 @@
+using System;
+using System.IO;
+using System.Collections.Generic;
+using Avalonia.Controls;
+using Avalonia.Platform.Storage;
+using Avalonia.Interactivity;
+using PostIt.ViewModels;
+
+namespace PostIt.Views;
+
+public partial class MyFilesPage : ContentPage
+{
+    public MyFilesPage()
+    {
+        InitializeComponent();
+    }
+
+    private async void Upload_Click(object? sender, RoutedEventArgs e)
+    {
+        var topLevel = TopLevel.GetTopLevel(this);
+        if (topLevel is null || DataContext is not MyFilesViewModel vm)
+            return;
+
+        var files = await topLevel.StorageProvider.OpenFilePickerAsync(new FilePickerOpenOptions
+        {
+            Title = "Choisir des fichiers à téléverser dans Mes fichiers",
+            AllowMultiple = true,
+        });
+
+        if (files.Count == 0)
+            return;
+
+        var uploads = new List<Yavsc.Api.Client.UploadFile>(files.Count);
+        foreach (var file in files)
+        {
+            await using var stream = await file.OpenReadAsync();
+            using var memory = new MemoryStream();
+            await stream.CopyToAsync(memory);
+            uploads.Add(new Yavsc.Api.Client.UploadFile(file.Name, memory.ToArray(), GetMimeType(file.Name)));
+        }
+
+        await vm.UploadAsync(uploads);
+    }
+
+    private static string GetMimeType(string fileName)
+    {
+        var ext = Path.GetExtension(fileName)?.ToLowerInvariant();
+        return ext switch
+        {
+            ".png" => "image/png",
+            ".jpg" or ".jpeg" => "image/jpeg",
+            ".webp" => "image/webp",
+            ".gif" => "image/gif",
+            ".pdf" => "application/pdf",
+            _ => "application/octet-stream"
+        };
+    }
+}