feat(sender): support draft editing flow in sender pages

EnvelopeGenerator.Server/EnvelopeGenerator.Server/Components/Pages/EnvelopeSenderEditorPage.razor

@@ -3,9 +3,12 @@
 @using DevExpress.Blazor.PdfViewer
 @using DevExpress.Blazor.Reporting.Models
 @using DevExpress.Blazor
+@using EnvelopeGenerator.Application.Common.Dto
+@using EnvelopeGenerator.Application.Envelopes.Commands
 @using EnvelopeGenerator.Application.EnvelopeReceivers.Commands
 @using EnvelopeGenerator.Server.Client.Services
 @using EnvelopeGenerator.Server.Services
+@using Microsoft.AspNetCore.WebUtilities
 @using Microsoft.AspNetCore.Components.Forms
 @using Microsoft.Extensions.Caching.Memory
 @inject IJSRuntime JSRuntime
@@ -14,6 +17,8 @@
 @inject ILogger<EnvelopeSenderEditorPage> Logger
 @inject EnvelopeReceiverPageDataService ReceiverPageDataService
 @inject EnvelopeReceiverService EnvelopeReceiverService
+@inject EnvelopeService EnvelopeService
+@inject IEnvelopeAuthService EnvelopeAuthService
 @inject IMemoryCache MemoryCache
 
 <link href="_content/DevExpress.Blazor.Themes/blazing-berry.bs5.min.css" rel="stylesheet" />
@@ -169,41 +174,55 @@
                                style="display: none;" />
                 </label>
 
-                @if (_pdfLoaded)
+                @if (_pdfLoaded && _signatureFields.Count > 0)
                 {
-                    @* Clear all fields *@
-                    @if (_signatureFields.Count > 0)
-                    {
-                        <button class="pdf-toolbar__btn pdf-toolbar__btn--reset"
-                                @onclick="ClearAllFieldsAsync"
-                                title="Alle Signaturfelder entfernen">
-                            <svg xmlns="http://www.w3.org/2000/svg" width="14" height="14" fill="currentColor" viewBox="0 0 16 16">
-                                <path d="M5.5 5.5A.5.5 0 0 1 6 6v6a.5.5 0 0 1-1 0V6a.5.5 0 0 1 .5-.5zm2.5 0a.5.5 0 0 1 .5.5v6a.5.5 0 0 1-1 0V6a.5.5 0 0 1 .5-.5zm3 .5a.5.5 0 0 0-1 0v6a.5.5 0 0 0 1 0V6z" />
-                                <path fill-rule="evenodd" d="M14.5 3a1 1 0 0 1-1 1H13v9a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2V4h-.5a1 1 0 0 1 0-2h3a1 1 0 0 1 1-1h3a1 1 0 0 1 1 1h3a1 1 0 0 1 1 1zM4.118 4 4 4.059V13a1 1 0 0 0 1 1h6a1 1 0 0 0 1-1V4.059L11.882 4H4.118zM2.5 3h11V2h-11v1z" />
-                            </svg>
-                        </button>
-                    }
-
-                    @* Save *@
-                    <button class="pdf-toolbar__btn pdf-toolbar__btn--success"
-                            @onclick="SaveAsync"
-                            disabled="@_isSaving"
-                            title="Speichern"
-                            style="background: linear-gradient(135deg,#059669,#047857); color:#fff; border-radius:6px; padding:0.3rem 0.75rem; font-size:0.75rem; font-weight:600; border:none;">
-                        @if (_isSaving)
-                        {
-                            <span class="spinner-border spinner-border-sm me-1" role="status"
-                                  style="width:0.8rem;height:0.8rem;border-width:2px;"></span>
-                        }
-                        else
-                        {
-                            <svg xmlns="http://www.w3.org/2000/svg" width="14" height="14" fill="currentColor" class="me-1" viewBox="0 0 16 16">
-                                <path d="M13.854 3.646a.5.5 0 0 1 0 .708l-7 7a.5.5 0 0 1-.708 0l-3.5-3.5a.5.5 0 1 1 .708-.708L6.5 10.293l6.646-6.647a.5.5 0 0 1 .708 0z" />
-                            </svg>
-                        }
-                        Speichern
+                    <button class="pdf-toolbar__btn pdf-toolbar__btn--reset"
+                            @onclick="ClearAllFieldsAsync"
+                            title="Alle Signaturfelder entfernen">
+                        <svg xmlns="http://www.w3.org/2000/svg" width="14" height="14" fill="currentColor" viewBox="0 0 16 16">
+                            <path d="M5.5 5.5A.5.5 0 0 1 6 6v6a.5.5 0 0 1-1 0V6a.5.5 0 0 1 .5-.5zm2.5 0a.5.5 0 0 1 .5.5v6a.5.5 0 0 1-1 0V6a.5.5 0 0 1 .5-.5zm3 .5a.5.5 0 0 0-1 0v6a.5.5 0 0 0 1 0V6z" />
+                            <path fill-rule="evenodd" d="M14.5 3a1 1 0 0 1-1 1H13v9a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2V4h-.5a1 1 0 0 1 0-2h3a1 1 0 0 1 1-1h3a1 1 0 0 1 1 1h3a1 1 0 0 1 1 1zM4.118 4 4 4.059V13a1 1 0 0 0 1 1h6a1 1 0 0 0 1-1V4.059L11.882 4H4.118zM2.5 3h11V2h-11v1z" />
+                        </svg>
                     </button>
                 }
+
+                <button class="pdf-toolbar__btn pdf-toolbar__btn--draft"
+                        @onclick="SaveDraftAsync"
+                        disabled="@_isSaving"
+                        title="Speichern">
+                    @if (_isSaving)
+                    {
+                        <span class="spinner-border spinner-border-sm me-1" role="status"
+                              style="width:0.8rem;height:0.8rem;border-width:2px;"></span>
+                    }
+                    else
+                    {
+                        <svg xmlns="http://www.w3.org/2000/svg" width="14" height="14" fill="currentColor" class="me-1" viewBox="0 0 16 16">
+                            <path d="M2 2a2 2 0 0 0-2 2v8a2 2 0 0 0 2 2h12a2 2 0 0 0 2-2V5.414A2 2 0 0 0 15.414 4L12 0.586A2 2 0 0 0 10.586 0H2zm9 1.5v2A1.5 1.5 0 0 1 9.5 7h-3A1.5 1.5 0 0 1 5 5.5v-4h5.586a1 1 0 0 1 .707.293L14.207 4.707A1 1 0 0 1 14.5 5.414V12a.5.5 0 0 1-.5.5H2a.5.5 0 0 1-.5-.5V4A.5.5 0 0 1 2 3.5h9z"/>
+                            <path d="M5.5 1.5v4a.5.5 0 0 0 .5.5h3a.5.5 0 0 0 .5-.5v-4h-4zM4 9a1 1 0 0 0-1 1v3h10v-3a1 1 0 0 0-1-1H4z"/>
+                        </svg>
+                    }
+                    <span class="pdf-toolbar__btn-text">Speichern</span>
+                </button>
+
+                <button class="pdf-toolbar__btn pdf-toolbar__btn--success"
+                        @onclick="SendAsync"
+                        disabled="@_isSaving"
+                        title="Umschlag senden"
+                        style="background: linear-gradient(135deg,#059669,#047857); color:#fff; border-radius:6px; padding:0.3rem 0.75rem; font-size:0.75rem; font-weight:600; border:none;">
+                    @if (_isSaving)
+                    {
+                        <span class="spinner-border spinner-border-sm me-1" role="status"
+                              style="width:0.8rem;height:0.8rem;border-width:2px;"></span>
+                    }
+                    else
+                    {
+                        <svg xmlns="http://www.w3.org/2000/svg" width="14" height="14" fill="currentColor" class="me-1" viewBox="0 0 16 16">
+                            <path d="M13.854 3.646a.5.5 0 0 1 0 .708l-7 7a.5.5 0 0 1-.708 0l-3.5-3.5a.5.5 0 1 1 .708-.708L6.5 10.293l6.646-6.647a.5.5 0 0 1 .708 0z" />
+                        </svg>
+                    }
+                    Senden
+                </button>
             </div>
         </div>
 
@@ -358,7 +377,7 @@
 
 @* ── Save result popup (success + error) ── *@
 <DxPopup @bind-Visible="_savePopupVisible"
-         HeaderText="@(_saveErrorMessage is null ? "Umschlag erstellt" : "Fehler")"
+         HeaderText="@(_saveErrorMessage is null ? _saveSuccessHeader : "Fehler")"
          Width="460px"
          MaxWidth="95vw"
          ShowFooter="true"
@@ -377,10 +396,10 @@
                 </div>
                 <div>
                     <p style="margin:0 0 0.4rem;font-weight:600;color:#1f2937;font-size:0.95rem;">
-                        Umschlag wurde erfolgreich erstellt.
+                        @_saveSuccessTitle
                     </p>
                     <p style="margin:0;color:#6b7280;font-size:0.85rem;line-height:1.5;">
-                        Der Umschlag wurde gespeichert und die Empfänger wurden benachrichtigt.
+                        @_saveSuccessBody
                     </p>
                 </div>
             </div>
@@ -410,12 +429,21 @@
         <div style="display:flex;gap:0.5rem;justify-content:flex-end;width:100%;padding:0.5rem 0;">
             @if (_saveErrorMessage is null)
             {
-                <button class="btn btn-primary"
-                        @onclick="GoToDashboard"
-                        style="background:linear-gradient(135deg,#059669,#047857);border:none;border-radius:6px;
-                                   padding:0.5rem 1.5rem;font-weight:600;color:#fff;">
-                    Zur Übersicht
+                <button class="btn btn-outline-secondary"
+                        @onclick="() => _savePopupVisible = false"
+                        style="border-radius:6px;padding:0.5rem 1.25rem;font-weight:500;">
+                    Schließen
                 </button>
+
+                @if (_saveNavigateToDashboard)
+                {
+                    <button class="btn btn-primary"
+                            @onclick="GoToDashboard"
+                            style="background:linear-gradient(135deg,#059669,#047857);border:none;border-radius:6px;
+                                       padding:0.5rem 1.5rem;font-weight:600;color:#fff;">
+                        Zur Übersicht
+                    </button>
+                }
             }
             else
             {
@@ -434,6 +462,9 @@
     [SupplyParameterFromQuery(Name = "esid")]
     public string? Esid { get; set; }
 
+    [SupplyParameterFromQuery(Name = "envelopeId")]
+    public int? EnvelopeId { get; set; }
+
     // ── Constants ──
     // Signature field size in PDF points (fixed): 1.77" × 1.96"
     const double SigWidthPt = 1.77 * 72;   // 127.44 pt
@@ -452,6 +483,9 @@
     string? _errorMessage;
     byte[]? _pdfBytes;          // Current rendered PDF (original + placeholders burned in)
     byte[]? _originalPdfBytes;  // Pristine upload — never modified, used as base for redraw
+    int? _loadedEnvelopeId;
+    int? _editingEnvelopeId;
+    bool _isLoadingEnvelopeForEdit;
 
     List<SignatureFieldDraft> _signatureFields = [];
     ReceiverDraft? _pendingReceiverForPlacement; // Set when user clicks "Signatur hinzufügen"
@@ -460,6 +494,10 @@
     bool _isSaving = false;
     bool _savePopupVisible = false;
     string? _saveErrorMessage = null;
+    string _saveSuccessHeader = "Erfolg";
+    string _saveSuccessTitle = "Vorgang erfolgreich abgeschlossen.";
+    string _saveSuccessBody = string.Empty;
+    bool _saveNavigateToDashboard = false;
 
     // ── Envelope metadata ──
     string _envelopeTitle = string.Empty;
@@ -481,6 +519,7 @@
 
     // ── Cache key helper ──
     string SessionKey => $"sender-editor:{Esid}";
+    bool IsEditMode => EnvelopeId.HasValue && EnvelopeId.Value > 0;
 
     // ── Lifecycle ──
 
@@ -500,12 +539,27 @@
         if (string.IsNullOrWhiteSpace(Esid))
         {
             var sid = Guid.NewGuid().ToString("N");
-            NavigationManager.NavigateTo($"/sender/editor?esid={sid}", forceLoad: false);
+            var editQuery = EnvelopeId.HasValue && EnvelopeId.Value > 0
+                ? $"&envelopeId={EnvelopeId.Value}"
+                : string.Empty;
+            NavigationManager.NavigateTo($"/sender/editor?esid={sid}{editQuery}", forceLoad: false);
         }
     }
 
-    protected override void OnParametersSet()
+    protected override async Task OnParametersSetAsync()
     {
+        if (EnvelopeId.HasValue && EnvelopeId.Value > 0)
+            _editingEnvelopeId = EnvelopeId.Value;
+
+        if (IsEditMode && _loadedEnvelopeId != EnvelopeId)
+        {
+            await LoadEnvelopeForEditAsync(EnvelopeId!.Value);
+            return;
+        }
+
+        if (IsEditMode)
+            return;
+
         // After the esid is set via query param, try to restore from cache.
         if (!string.IsNullOrWhiteSpace(Esid)
             && MemoryCache.TryGetValue(SessionKey, out EditorSessionData? cached)
@@ -525,6 +579,90 @@
         }
     }
 
+    async Task LoadEnvelopeForEditAsync(int envelopeId)
+    {
+        if (_isLoadingEnvelopeForEdit)
+            return;
+
+        _isLoadingEnvelopeForEdit = true;
+        _errorMessage = null;
+
+        try
+        {
+            var user = EnvelopeAuthService.GetCurrentUser();
+            if (user?.Identity is null || !user.Identity.IsAuthenticated)
+                throw new InvalidOperationException("Sender is not authenticated.");
+
+            var envelopes = await EnvelopeService.GetAsync(id: envelopeId);
+            var envelope = envelopes?.FirstOrDefault()
+                ?? throw new InvalidOperationException($"Envelope {envelopeId} not found.");
+
+            var document = await ReceiverPageDataService.GetDocumentDetailsOfSenderAsync(user, envelopeId);
+            if (document.ByteData is null || document.ByteData.Length == 0)
+                throw new InvalidOperationException($"Document for envelope {envelopeId} is missing.");
+
+            _envelopeTitle = envelope.Title ?? string.Empty;
+            _envelopeMessage = envelope.Message ?? string.Empty;
+
+            var envelopeReceivers = envelope.EnvelopeReceivers?.ToList() ?? [];
+            _receivers = envelopeReceivers
+                .Select((er, index) => new ReceiverDraft(
+                    Guid.NewGuid(),
+                    er.Name ?? er.Receiver?.EmailAddress ?? $"Receiver {er.ReceiverId}",
+                    er.Receiver?.EmailAddress ?? string.Empty,
+                    string.Empty,
+                    ReceiverPalette[index % ReceiverPalette.Length]))
+                .ToList();
+
+            var receiverById = envelopeReceivers.ToDictionary(er => er.ReceiverId, er => er);
+            var colorByEmail = _receivers
+                .Where(r => !string.IsNullOrWhiteSpace(r.Email))
+                .GroupBy(r => r.Email, StringComparer.OrdinalIgnoreCase)
+                .ToDictionary(g => g.Key, g => g.First().Color, StringComparer.OrdinalIgnoreCase);
+
+            _signatureFields = (document.Elements ?? Enumerable.Empty<DocReceiverElementDto>())
+                .Select(element =>
+                {
+                    receiverById.TryGetValue(element.ReceiverId, out var envelopeReceiver);
+
+                    var receiverName = envelopeReceiver?.Name
+                        ?? envelopeReceiver?.Receiver?.EmailAddress
+                        ?? element.FullName
+                        ?? $"Receiver {element.ReceiverId}";
+
+                    var receiverEmail = envelopeReceiver?.Receiver?.EmailAddress;
+                    var color = (!string.IsNullOrWhiteSpace(receiverEmail) && colorByEmail.TryGetValue(receiverEmail, out var receiverColor))
+                        ? receiverColor
+                        : ReceiverPalette[Math.Abs(element.ReceiverId) % ReceiverPalette.Length];
+
+                    return new SignatureFieldDraft(
+                        XPt: element.X * 72.0,
+                        YPt: element.Y * 72.0,
+                        Page: element.Page,
+                        ReceiverName: receiverName,
+                        Color: color);
+                })
+                .ToList();
+
+            _originalPdfBytes = document.ByteData;
+            _pdfBytes = DrawPlaceholders(_originalPdfBytes, _signatureFields);
+            _pdfLoaded = true;
+            _fileName = $"Envelope-{envelopeId}.pdf";
+            _pendingReceiverForPlacement = null;
+            _loadedEnvelopeId = envelopeId;
+            _editingEnvelopeId = envelopeId;
+        }
+        catch (Exception ex)
+        {
+            Logger.LogError(ex, "Failed to load envelope {EnvelopeId} for edit mode", envelopeId);
+            _errorMessage = $"Fehler beim Laden des Umschlags #{envelopeId}: {ex.Message}";
+        }
+        finally
+        {
+            _isLoadingEnvelopeForEdit = false;
+        }
+    }
+
     // ── PDF upload ──
     async Task OnPdfFileSelectedAsync(InputFileChangeEventArgs e)
     {
@@ -670,8 +808,48 @@
         NavigationManager.NavigateTo("/sender");
     }
 
-    // ── Save — POST /api/EnvelopeReceiver ──
-    async Task SaveAsync()
+    async Task SaveDraftAsync()
+    {
+        _isSaving = true;
+        _saveErrorMessage = null;
+        await InvokeAsync(StateHasChanged);
+
+        try
+        {
+            var previousEnvelopeId = EnvelopeId;
+            var command = BuildSaveDraftCommand();
+            Logger.LogInformation("[SenderEditor] Saving draft. EnvelopeId={EnvelopeId} IsEditMode={IsEditMode}", command.EnvelopeId, IsEditMode);
+            var result = await EnvelopeService.SaveDraftAsync(command);
+
+            if (result is null)
+                throw new InvalidOperationException("Draft save did not return a result.");
+
+            EnvelopeId = result.EnvelopeId;
+            _loadedEnvelopeId = result.EnvelopeId;
+            _editingEnvelopeId = result.EnvelopeId;
+
+            if (previousEnvelopeId != result.EnvelopeId)
+            {
+                var sid = string.IsNullOrWhiteSpace(Esid) ? Guid.NewGuid().ToString("N") : Esid;
+                NavigationManager.NavigateTo($"/sender/editor?esid={sid}&envelopeId={result.EnvelopeId}", forceLoad: false);
+            }
+
+            NavigationManager.NavigateTo("/sender", forceLoad: false);
+        }
+        catch (Exception ex)
+        {
+            Logger.LogError(ex, "[SenderEditor] Failed to save draft");
+            _saveErrorMessage = ex.Message;
+            _savePopupVisible = true;
+        }
+        finally
+        {
+            _isSaving = false;
+        }
+    }
+
+    // ── Send — POST /api/EnvelopeReceiver ──
+    async Task SendAsync()
     {
         // ── Validation ──
         _titleTouched = true;
@@ -763,6 +941,10 @@
 
             // Success — show popup; GoToDashboard clears cache and navigates
             _saveErrorMessage = null;
+            _saveSuccessHeader = "Umschlag erstellt";
+            _saveSuccessTitle = "Umschlag wurde erfolgreich erstellt.";
+            _saveSuccessBody = "Der Umschlag wurde gespeichert und die Empfänger wurden benachrichtigt.";
+            _saveNavigateToDashboard = true;
             _savePopupVisible = true;
         }
         catch (Exception ex)
@@ -777,6 +959,70 @@
         }
     }
 
+    SaveEnvelopeDraftCommand BuildSaveDraftCommand()
+    {
+        var envelopeId = _editingEnvelopeId
+            ?? EnvelopeId
+            ?? _loadedEnvelopeId
+            ?? GetEnvelopeIdFromCurrentUri();
+
+        if (IsEditMode && envelopeId is null)
+            throw new InvalidOperationException("Edit mode envelope id is missing.");
+
+        var docBase64 = _originalPdfBytes is { Length: > 0 }
+            ? Convert.ToBase64String(_originalPdfBytes)
+            : null;
+
+        var receiverCommands = _receivers.Select(receiver =>
+        {
+            var fields = _signatureFields
+                .Where(f => f.ReceiverName == receiver.FullName)
+                .Select(f => new SaveEnvelopeDraftFieldDto(
+                    X: f.XPt / 72.0,
+                    Y: f.YPt / 72.0,
+                    Page: f.Page))
+                .ToList();
+
+            return new SaveEnvelopeDraftReceiverDto(
+                EmailAddress: receiver.Email,
+                Name: receiver.FullName,
+                PhoneNumber: string.IsNullOrWhiteSpace(receiver.PhoneNumber) ? null : receiver.PhoneNumber,
+                Fields: fields);
+        }).ToList();
+
+        return new SaveEnvelopeDraftCommand
+        {
+            EnvelopeId = envelopeId,
+            Title = _envelopeTitle,
+            Message = _envelopeMessage,
+            TFAEnabled = false,
+            Document = string.IsNullOrWhiteSpace(docBase64) ? null : new SaveEnvelopeDraftDocumentDto(docBase64),
+            Receivers = receiverCommands
+        };
+    }
+
+    int? GetEnvelopeIdFromCurrentUri()
+    {
+        try
+        {
+            var uri = NavigationManager.ToAbsoluteUri(NavigationManager.Uri);
+            if (string.IsNullOrWhiteSpace(uri.Query))
+                return null;
+
+            var query = QueryHelpers.ParseQuery(uri.Query);
+            if (!query.TryGetValue("envelopeId", out var raw))
+                return null;
+
+            return int.TryParse(raw.ToString(), out var id) && id > 0
+                ? id
+                : null;
+        }
+        catch
+        {
+            return null;
+        }
+    }
+
     // ── Cache persistence ──
     void PersistSession()
     {

EnvelopeGenerator.Server/EnvelopeGenerator.Server/Components/Pages/EnvelopeSenderPage.razor

@@ -73,7 +73,7 @@
                     Neuer Umschlag
                 </button>
 
-                <button class="sender-btn" @onclick="EditEnvelope" disabled="@(_selectedEnvelope == null || IsEnvelopeSent(_selectedEnvelope))" title="Ausgewählten Umschlag bearbeiten">
+                <button class="sender-btn" @onclick="EditEnvelope" disabled="@(_selectedEnvelope == null || !IsEnvelopeEditable(_selectedEnvelope))" title="Ausgewählten Umschlag bearbeiten">
                     <svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" fill="currentColor" viewBox="0 0 16 16">
                         <path d="M12.146.146a.5.5 0 0 1 .708 0l3 3a.5.5 0 0 1 0 .708l-10 10a.5.5 0 0 1-.168.11l-5 2a.5.5 0 0 1-.65-.65l2-5a.5.5 0 0 1 .11-.168l10-10zM11.207 2.5 13.5 4.793 14.793 3.5 12.5 1.207 11.207 2.5zm1.586 3L10.5 3.207 4 9.707V10h.5a.5.5 0 0 1 .5.5v.5h.5a.5.5 0 0 1 .5.5v.5h.293l6.5-6.5zm-9.761 5.175-.106.106-1.528 3.821 3.821-1.528.106-.106A.5.5 0 0 1 5 12.5V12h-.5a.5.5 0 0 1-.5-.5V11h-.5a.5.5 0 0 1-.468-.325z" />
                     </svg>
@@ -728,7 +728,9 @@
     void EditEnvelope()
     {
         if (_selectedEnvelope == null) return;
-        // TODO: Navigate to envelope editor
+        if (!IsEnvelopeEditable(_selectedEnvelope)) return;
+
+        Navigation.NavigateTo($"/sender/editor?envelopeId={_selectedEnvelope.Id}");
     }
 
     void DeleteEnvelope()
@@ -796,6 +798,12 @@
         return status >= EnvelopeStatus.EnvelopeQueued;
     }
 
+    bool IsEnvelopeEditable(EnvelopeDto envelope)
+    {
+        var status = (EnvelopeStatus)envelope.Status;
+        return status is EnvelopeStatus.EnvelopeCreated or EnvelopeStatus.EnvelopeSaved;
+    }
+
     (string Label, string CssClass, string DotColor) GetStatusInfo(EnvelopeStatus status)
     {
         return status switch

EnvelopeGenerator.Server/EnvelopeGenerator.Server/Services/EnvelopeReceiverPageDataService.cs

@@ -49,6 +49,14 @@ public class EnvelopeReceiverPageDataService(
             : throw new NotFoundException($"Document for envelope {envelopeId} not found.");
     }
 
+    /// <summary>
+    /// Loads the full document DTO (including receiver elements) for the authenticated sender.
+    /// </summary>
+    public async Task<DocumentDto> GetDocumentDetailsOfSenderAsync(ClaimsPrincipal user, int envelopeId, CancellationToken cancellationToken = default)
+    {
+        return await mediator.Send(new ReadDocumentQuery(EnvelopeId: envelopeId, UserId: user.SenderId()), cancellationToken);
+    }
+
     /// <summary>
     /// Loads the current receiver's signature placeholders.
     /// </summary>

EnvelopeGenerator.Server/EnvelopeGenerator.Server/wwwroot/css/envelope-viewer.css

@@ -542,6 +542,40 @@ body.resizing {
     color: white;
 }
 
+/* Draft save button for sender editor */
+.pdf-toolbar__btn--draft {
+    display: flex;
+    align-items: center;
+    gap: 0.35rem;
+    min-width: auto;
+    padding: 0.3rem 0.75rem;
+    font-size: 0.75rem;
+    font-weight: 600;
+    color: #0f4c81;
+    border: 1px solid rgba(14, 165, 233, 0.34);
+    background: linear-gradient(135deg, rgba(14, 165, 233, 0.12) 0%, rgba(2, 132, 199, 0.1) 100%);
+}
+
+.pdf-toolbar__btn--draft:hover:not(:disabled) {
+    color: #ffffff;
+    border-color: transparent;
+    background: linear-gradient(135deg, #0ea5e9 0%, #0284c7 100%);
+    box-shadow: 0 4px 12px rgba(2, 132, 199, 0.28);
+}
+
+.pdf-toolbar__btn--draft:disabled {
+    color: #64748b;
+}
+
+.pdf-toolbar__btn--draft svg {
+    flex-shrink: 0;
+    transition: color 0.2s ease;
+}
+
+.pdf-toolbar__btn--draft .pdf-toolbar__btn-text {
+    color: inherit;
+}
+
 /* Signature Change Button */
 .pdf-toolbar__btn--signature-change {
     display: flex;