feat(data): add GetConfigAsync and SetConfigAsync to ListRepository

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

tests/ClaudeDo.Worker.Tests/Repositories/ListRepositoryConfigTests.cs

@@ -0,0 +1,61 @@
+using ClaudeDo.Data.Models;
+using ClaudeDo.Data.Repositories;
+using ClaudeDo.Worker.Tests.Infrastructure;
+
+namespace ClaudeDo.Worker.Tests.Repositories;
+
+public sealed class ListRepositoryConfigTests : IDisposable
+{
+    private readonly DbFixture _db = new();
+    private readonly ListRepository _repo;
+    private readonly string _listId;
+
+    public ListRepositoryConfigTests()
+    {
+        _repo = new ListRepository(_db.Factory);
+        _listId = Guid.NewGuid().ToString();
+        _repo.AddAsync(new ListEntity
+        {
+            Id = _listId, Name = "Test", CreatedAt = DateTime.UtcNow
+        }).GetAwaiter().GetResult();
+    }
+
+    [Fact]
+    public async Task GetConfig_Returns_Null_When_No_Config()
+    {
+        var config = await _repo.GetConfigAsync(_listId);
+        Assert.Null(config);
+    }
+
+    [Fact]
+    public async Task SetConfig_And_GetConfig_Roundtrips()
+    {
+        var config = new ListConfigEntity
+        {
+            ListId = _listId,
+            Model = "sonnet-4-6",
+            SystemPrompt = "You are helpful.",
+            AgentPath = "/home/user/.todo-app/agents/dev.md",
+        };
+        await _repo.SetConfigAsync(config);
+
+        var fetched = await _repo.GetConfigAsync(_listId);
+        Assert.NotNull(fetched);
+        Assert.Equal("sonnet-4-6", fetched.Model);
+        Assert.Equal("You are helpful.", fetched.SystemPrompt);
+        Assert.Equal("/home/user/.todo-app/agents/dev.md", fetched.AgentPath);
+    }
+
+    [Fact]
+    public async Task SetConfig_Upserts_On_Duplicate()
+    {
+        await _repo.SetConfigAsync(new ListConfigEntity { ListId = _listId, Model = "opus-4-6" });
+        await _repo.SetConfigAsync(new ListConfigEntity { ListId = _listId, Model = "haiku-4-5" });
+
+        var fetched = await _repo.GetConfigAsync(_listId);
+        Assert.NotNull(fetched);
+        Assert.Equal("haiku-4-5", fetched.Model);
+    }
+
+    public void Dispose() => _db.Dispose();
+}