docs(runner): correct the findings-pointer comment

src/ClaudeDo.Worker/Runner/TaskRunner.cs

@@ -665,8 +665,10 @@ public sealed class TaskRunner
         => 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
+    /// Points the run at the project's findings index. Deliberately terse and emitted only when the
-    /// prefix of every message in the run, so its cost is multiplied by the turn count.
+    /// index exists: it enters the prefix of every message in the run, so its cost is multiplied by
+    /// the turn count. The closing nudge to record findings is what keeps the store fed — do not drop
+    /// it when trimming.
     /// </summary>
     internal static string? BuildFindingsPointer(string? workingDir)
     {