Return the created API key from POST /Auth/Keys (#17155)

* Return the created API key from POST /Auth/Keys

* Keep the other API key fields in the DTO

tests/Jellyfin.Server.Implementations.Tests/Security/AuthenticationManagerTests.cs

@@ -0,0 +1,80 @@
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+using Jellyfin.Database.Implementations;
+using Jellyfin.Database.Implementations.Locking;
+using Jellyfin.Database.Providers.Sqlite;
+using Jellyfin.Server.Implementations.Security;
+using Microsoft.Data.Sqlite;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Logging.Abstractions;
+using Moq;
+using Xunit;
+
+namespace Jellyfin.Server.Implementations.Tests.Security
+{
+    public sealed class AuthenticationManagerTests : IDisposable
+    {
+        private readonly SqliteConnection _connection;
+        private readonly DbContextOptions<JellyfinDbContext> _dbOptions;
+        private readonly AuthenticationManager _authenticationManager;
+
+        public AuthenticationManagerTests()
+        {
+            _connection = new SqliteConnection("Data Source=:memory:");
+            _connection.Open();
+
+            _dbOptions = new DbContextOptionsBuilder<JellyfinDbContext>()
+                .UseSqlite(_connection)
+                .Options;
+
+            // Create the schema
+            using var ctx = CreateDbContext();
+            ctx.Database.EnsureCreated();
+
+            var factory = new Mock<IDbContextFactory<JellyfinDbContext>>();
+            factory.Setup(f => f.CreateDbContext()).Returns(CreateDbContext);
+            factory.Setup(f => f.CreateDbContextAsync(It.IsAny<CancellationToken>()))
+                .ReturnsAsync(CreateDbContext);
+
+            _authenticationManager = new AuthenticationManager(factory.Object);
+        }
+
+        public void Dispose()
+        {
+            _connection.Dispose();
+        }
+
+        private JellyfinDbContext CreateDbContext()
+        {
+            return new JellyfinDbContext(
+                _dbOptions,
+                NullLogger<JellyfinDbContext>.Instance,
+                new SqliteDatabaseProvider(null!, NullLogger<SqliteDatabaseProvider>.Instance),
+                new NoLockBehavior(NullLogger<NoLockBehavior>.Instance));
+        }
+
+        [Fact]
+        public async Task CreateApiKey_ReturnsInfoMatchingStoredKey()
+        {
+            var created = await _authenticationManager.CreateApiKey("test-app");
+
+            Assert.Equal("test-app", created.AppName);
+            Assert.False(string.IsNullOrEmpty(created.AccessToken));
+
+            var keys = await _authenticationManager.GetApiKeys();
+            var stored = Assert.Single(keys);
+            Assert.Equal(created.AppName, stored.AppName);
+            Assert.Equal(created.AccessToken, stored.AccessToken);
+        }
+
+        [Fact]
+        public async Task CreateApiKey_WithMultipleKeys_ReturnsDistinctTokens()
+        {
+            var first = await _authenticationManager.CreateApiKey("app1");
+            var second = await _authenticationManager.CreateApiKey("app2");
+
+            Assert.NotEqual(first.AccessToken, second.AccessToken);
+        }
+    }
+}