feat(core): add shared auth models for encrypted login

NEW/src/JdeScoping.Core/Models/Auth/EncryptedLoginRequest.cs

@@ -0,0 +1,7 @@
+namespace JdeScoping.Core.Models.Auth;
+
+/// <summary>
+/// Encrypted login payload sent from client to API.
+/// </summary>
+/// <param name="EncryptedData">Base64-encoded RSA-encrypted JSON of LoginModel</param>
+public record EncryptedLoginRequest(string EncryptedData);

NEW/src/JdeScoping.Core/Models/Auth/LoginModel.cs

@@ -0,0 +1,15 @@
+using System.ComponentModel.DataAnnotations;
+
+namespace JdeScoping.Core.Models.Auth;
+
+/// <summary>
+/// Login credentials model shared by Client and API.
+/// </summary>
+public class LoginModel
+{
+    [Required(ErrorMessage = "Username is required")]
+    public string Username { get; set; } = string.Empty;
+
+    [Required(ErrorMessage = "Password is required")]
+    public string Password { get; set; } = string.Empty;
+}

NEW/src/JdeScoping.Core/Models/Auth/LoginResultModel.cs

@@ -0,0 +1,14 @@
+using JdeScoping.Core.Models;
+
+namespace JdeScoping.Core.Models.Auth;
+
+/// <summary>
+/// Result returned from login API endpoint.
+/// </summary>
+/// <param name="Success">Whether authentication succeeded</param>
+/// <param name="ErrorMessage">Error message if failed</param>
+/// <param name="User">User info if successful</param>
+public record LoginResultModel(
+    bool Success,
+    string? ErrorMessage,
+    UserInfo? User);

NEW/src/JdeScoping.Core/Models/Auth/PublicKeyResponse.cs

@@ -0,0 +1,7 @@
+namespace JdeScoping.Core.Models.Auth;
+
+/// <summary>
+/// Server's RSA public key for client-side encryption.
+/// </summary>
+/// <param name="PublicKeyPem">PEM-encoded RSA public key</param>
+public record PublicKeyResponse(string PublicKeyPem);

NEW/src/JdeScoping.DataSync/Fetchers/MockDataFetcher.cs

@@ -1,40 +0,0 @@
-using System.Runtime.CompilerServices;
-using JdeScoping.DataSync.Contracts;
-using Microsoft.Extensions.Logging;
-
-namespace JdeScoping.DataSync.Fetchers;
-
-/// <summary>
-/// Base class for mock data fetchers used during development.
-/// Returns empty results - real implementations will query source databases.
-/// </summary>
-/// <typeparam name="TEntity">The entity type being fetched.</typeparam>
-public abstract class MockDataFetcher<TEntity> : IDataFetcher<TEntity> where TEntity : class
-{
-    /// <summary>
-    /// Logger instance.
-    /// </summary>
-    protected readonly ILogger Logger;
-
-    /// <summary>
-    /// Initializes a new instance of the <see cref="MockDataFetcher{TEntity}"/> class.
-    /// </summary>
-    protected MockDataFetcher(ILogger logger)
-    {
-        Logger = logger ?? throw new ArgumentNullException(nameof(logger));
-    }
-
-    /// <inheritdoc/>
-    public virtual async IAsyncEnumerable<TEntity> FetchAsync(
-        DateTime? minimumDt,
-        [EnumeratorCancellation] CancellationToken cancellationToken = default)
-    {
-        Logger.LogWarning(
-            "MockDataFetcher<{EntityType}> returning empty results. Implement real fetcher for production.",
-            typeof(TEntity).Name);
-
-        // Return empty enumerable - real implementations will query source databases
-        await Task.CompletedTask;
-        yield break;
-    }
-}