fix(mcp): register ticket import tools in the external MCP container

The external MCP server has its own DI container; TicketMcpTools could not
resolve TicketImportService there, so both tools failed at runtime. Also
surface a skipped import in the prime outcome and treat a sweep where every
project board fails as an error instead of an empty backlog.

tests/ClaudeDo.Worker.Tests/Prime/PrimeRunnerTests.cs

@@ -311,6 +311,7 @@ public class PrimeRunnerTests : IDisposable
         var outcome = await runner.FireAsync(Schedule(PrimeActionKind.ImportTickets), CancellationToken.None);
 
         Assert.True(outcome.Success);
+        Assert.Contains("not configured", outcome.Message);
         var only = Assert.Single(claude.AllArguments);
         Assert.Contains(DailyPrepPrompt.SetMyDayTool, only);
     }

tests/ClaudeDo.Worker.Tests/Tickets/TicketImportAllTests.cs

@@ -156,6 +156,15 @@ public sealed class TicketImportAllTests : IDisposable
         Assert.Contains("Hub Lagertechnik", r.SkippedReason);
     }
 
+    [Fact]
+    public async Task GetCandidates_throws_when_no_board_is_readable()
+    {
+        var (import, _) = await HarnessAsync(respond: r =>
+            r.RequestUri!.AbsolutePath.Contains("/Board/project/") ? (HttpStatusCode.Forbidden, "") : Respond(r));
+
+        await Assert.ThrowsAsync<TicketApiException>(() => import.GetCandidatesAsync(CancellationToken.None));
+    }
+
     [Fact]
     public async Task GetCandidates_throws_when_not_configured()
     {
@@ -214,7 +223,8 @@ public sealed class TicketImportAllTests : IDisposable
         return (HttpStatusCode.NotFound, "");
     }
 
-    private async Task<(TicketImportService Import, ClaudeDoDbContext Ctx)> HarnessAsync(bool configured = true)
+    private async Task<(TicketImportService Import, ClaudeDoDbContext Ctx)> HarnessAsync(
+        bool configured = true, Func<HttpRequestMessage, (HttpStatusCode, string)>? respond = null)
     {
         var db = new DbFixture();
         _dbs.Add(db);
@@ -240,7 +250,7 @@ public sealed class TicketImportAllTests : IDisposable
 
         var clients = new TicketClientFactory(
             new TicketSystemConfig(worker, patStore),
-            new StubHttpClientFactory(new StubHandler(Respond)),
+            new StubHttpClientFactory(new StubHandler(respond ?? Respond)),
             NullLogger<BandelTicketClient>.Instance);
         var import = new TicketImportService(clients, factory, NullLogger<TicketImportService>.Instance);
         return (import, factory.CreateDbContext());