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

src/ClaudeDo.Worker/Runner/TaskRunner.cs

@@ -123,7 +123,7 @@ public sealed class TaskRunner
             var wtCtx = prep.WtCtx;
             var runDir = prep.RunDir!;
 
-            var resolvedConfig = await ResolveConfigAsync(task, listConfig, null, ct);
+            var resolvedConfig = await ResolveConfigAsync(task, list, listConfig, null, ct);
 
             // Every run gets a per-run MCP identity so the agent can ask the user a
             // mid-run question via AskUser. Improvement-eligible (standalone top-level)
@@ -237,7 +237,7 @@ public sealed class TaskRunner
             worktree = await wtRepo.GetByTaskIdAsync(taskId, ct);
         }
 
-        var resolvedConfig = await ResolveConfigAsync(task, listConfig, lastRun.SessionId, ct);
+        var resolvedConfig = await ResolveConfigAsync(task, list, listConfig, lastRun.SessionId, ct);
 
         // Determine run directory from existing worktree or sandbox.
         string runDir;
@@ -556,7 +556,7 @@ public sealed class TaskRunner
     }
 
     private async Task<ClaudeRunConfig> ResolveConfigAsync(
-        TaskEntity task, ListConfigEntity? listConfig, string? resumeSessionId, CancellationToken ct)
+        TaskEntity task, ListEntity list, ListConfigEntity? listConfig, string? resumeSessionId, CancellationToken ct)
     {
         AppSettingsEntity global;
         using (var ctx = _dbFactory.CreateDbContext())
@@ -572,8 +572,11 @@ public sealed class TaskRunner
         var isImprovementChild = task.ParentTaskId is not null && task.CreatedBy == task.ParentTaskId;
         var improvementPrompt = isImprovementChild ? PromptFiles.ReadOrDefault(PromptKind.ImprovementChild) : null;
 
+        var findingsPointer = BuildFindingsPointer(list.WorkingDir);
+
         var instructions = MergeInstructions(
-            systemFile, improvementPrompt, global.DefaultClaudeInstructions, listConfig?.SystemPrompt, task.SystemPrompt);
+            systemFile, improvementPrompt, global.DefaultClaudeInstructions, findingsPointer,
+            listConfig?.SystemPrompt, task.SystemPrompt);
 
         var requestedSkills = UnionSkillNames(task.SessionSkills, listConfig?.SessionSkills, global.SessionSkills);
         var skillNames = await FilterToInstalledSkillsAsync(task.Id, requestedSkills, ct);
@@ -661,6 +664,20 @@ public sealed class TaskRunner
     internal static int? ResolveMaxTurns(int? taskTurns, int? listTurns, int globalDefault, int ceiling)
         => Math.Min(taskTurns ?? listTurns ?? globalDefault, ceiling);
 
+    /// <summary>
+    /// Points the run at the project's findings index. Kept to one sentence on purpose: it enters the
+    /// prefix of every message in the run, so its cost is multiplied by the turn count.
+    /// </summary>
+    internal static string? BuildFindingsPointer(string? workingDir)
+    {
+        if (string.IsNullOrWhiteSpace(workingDir)) return null;
+        var index = Path.Combine(workingDir, ".claudedo", "INDEX.md");
+        if (!File.Exists(index)) return null;
+        return $"Known traps for this project are indexed at {index}. Read that index before exploring "
+             + "the code, and open only the findings that touch your task. When you hit a lasting, "
+             + "non-obvious trap yourself, record it with the save_finding tool.";
+    }
+
     public static string MergeInstructions(params string?[] parts)
     {
         var trimmed = parts

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); }
+    }
 }