feat(runner): point autonomous runs at the findings index

tests/ClaudeDo.Worker.Tests/Runner/ClaudeArgsBuilderTests.cs

@@ -244,4 +244,34 @@ public sealed class MergeInstructionsTests
         var s = ClaudeDo.Worker.Runner.TaskRunner.MergeInstructions("   ", "L", "\t\n");
         Assert.Equal("L", s);
     }
+
+    [Fact]
+    public void BuildFindingsPointer_ReturnsNullWhenNoIndexExists()
+    {
+        var dir = Path.Combine(Path.GetTempPath(), "cdo-ptr-" + Guid.NewGuid().ToString("N"));
+        Directory.CreateDirectory(dir);
+        try
+        {
+            Assert.Null(ClaudeDo.Worker.Runner.TaskRunner.BuildFindingsPointer(dir));
+            Assert.Null(ClaudeDo.Worker.Runner.TaskRunner.BuildFindingsPointer(null));
+            Assert.Null(ClaudeDo.Worker.Runner.TaskRunner.BuildFindingsPointer("  "));
+        }
+        finally { Directory.Delete(dir, recursive: true); }
+    }
+
+    [Fact]
+    public void BuildFindingsPointer_MentionsTheIndexPathWhenItExists()
+    {
+        var dir = Path.Combine(Path.GetTempPath(), "cdo-ptr-" + Guid.NewGuid().ToString("N"));
+        Directory.CreateDirectory(Path.Combine(dir, ".claudedo"));
+        File.WriteAllText(Path.Combine(dir, ".claudedo", "INDEX.md"), "# Findings\n");
+        try
+        {
+            var pointer = ClaudeDo.Worker.Runner.TaskRunner.BuildFindingsPointer(dir);
+            Assert.NotNull(pointer);
+            Assert.Contains("INDEX.md", pointer);
+            Assert.Contains("save_finding", pointer);
+        }
+        finally { Directory.Delete(dir, recursive: true); }
+    }
 }