Contacts management.

Wino.Core.Domain/Entities/Shared/AccountContact.cs

@@ -25,7 +25,16 @@ public class AccountContact : IEquatable<AccountContact>
     public string Name { get; set; }
 
     /// <summary>
-    /// Base64 encoded profile image of the contact.
+    /// File ID for the contact picture stored on disk.
+    /// The actual file lives at {ApplicationDataFolderPath}/contacts/{ContactPictureFileId}.jpg.
+    /// Preferred over Base64ContactPicture — allows native BitmapImage file loading and avoids SQLite bloat.
+    /// </summary>
+    public Guid? ContactPictureFileId { get; set; }
+
+    /// <summary>
+    /// Legacy base64 encoded profile image of the contact.
+    /// For user-set contact pictures: migrate to file storage via ContactPictureFileId instead.
+    /// Still used for OAuth account profile pictures (MailAccount.Base64ProfilePictureData).
     /// </summary>
     public string Base64ContactPicture { get; set; }
 

Wino.Core.Domain/Entities/Shared/ContactGroup.cs

@@ -0,0 +1,19 @@
+using System;
+using SQLite;
+
+namespace Wino.Core.Domain.Entities.Shared;
+
+/// <summary>
+/// A named group of contacts that can be expanded to individual addresses during mail composition.
+/// </summary>
+public class ContactGroup
+{
+    [PrimaryKey]
+    public Guid Id { get; set; }
+
+    /// <summary>Display name of the group (e.g., "Team Alpha", "Family").</summary>
+    public string Name { get; set; }
+
+    /// <summary>Optional description for the group.</summary>
+    public string Description { get; set; }
+}

Wino.Core.Domain/Entities/Shared/ContactGroupMember.cs

@@ -0,0 +1,21 @@
+using System;
+using SQLite;
+
+namespace Wino.Core.Domain.Entities.Shared;
+
+/// <summary>
+/// Associates an e-mail address with a <see cref="ContactGroup"/>.
+/// </summary>
+public class ContactGroupMember
+{
+    [PrimaryKey, AutoIncrement]
+    public int Id { get; set; }
+
+    /// <summary>Group this member belongs to.</summary>
+    [Indexed]
+    public Guid GroupId { get; set; }
+
+    /// <summary>E-mail address of the member (FK to AccountContact.Address).</summary>
+    [Indexed]
+    public string MemberAddress { get; set; }
+}