bound reply chains in list output to 3 most recent

pi/extensions/todo/state.test.ts

@@ -407,3 +407,19 @@ test("list output keeps active todos first and caps completed history", () => {
   assert.doesNotMatch(result, /done task 1\b/)
   assert.match(result, /done task 30\b/)
 })
+
+test("reply chains are bounded in list output with an omission indicator", () => {
+  const manyReplies = Array.from({ length: 12 }, (_, i) => `reply ${i + 1}`)
+  const todo: Todo = {
+    id: 1,
+    text: "task with long reply history",
+    status: "in_progress",
+    replies: manyReplies,
+  }
+  const result = formatTodoList([todo])
+  assert.match(result, /reply 12/)
+  assert.match(result, /reply 11/)
+  assert.match(result, /reply 10/)
+  assert.doesNotMatch(result, /reply 9\b/)
+  assert.match(result, /9 earlier replies omitted/)
+})

pi/extensions/todo/state.ts

@@ -562,6 +562,7 @@ export const todoStatusMark: (status: TodoStatus) => string = status =>
   })[status]
 
 const COMPLETED_HISTORY_LIMIT = 10
+const REPLY_HISTORY_LIMIT = 3
 
 export const formatTodoList: (todos: ReadonlyArray<Todo>) => string = todos => {
   if (todos.length === 0) return "No todos"
@@ -573,8 +574,19 @@ export const formatTodoList: (todos: ReadonlyArray<Todo>) => string = todos => {
           ? ` — deferred until ${new Date(todo.remindAt).toISOString()}`
           : ""
     const replies =
-      todo.replies?.map(reply => `\n    ↳ reply: ${reply}`).join("") ?? ""
-    return `${todoStatusMark(todo.status)} #${todo.id}: ${todo.text}${detail}${replies}`
+      (todo.replies?.length ?? 0) > 0
+        ? [
+            ...((todo.replies?.length ?? 0) > REPLY_HISTORY_LIMIT
+              ? [
+                  `    … ${(todo.replies?.length ?? 0) - REPLY_HISTORY_LIMIT} earlier ${(todo.replies?.length ?? 0) - REPLY_HISTORY_LIMIT === 1 ? "reply" : "replies"} omitted`,
+                ]
+              : []),
+            ...(todo.replies ?? [])
+              .slice(-REPLY_HISTORY_LIMIT)
+              .map(reply => `    ↳ reply: ${reply}`),
+          ].join("\n")
+        : ""
+    return `${todoStatusMark(todo.status)} #${todo.id}: ${todo.text}${detail}${replies ? "\n" + replies : ""}`
   }
   // Active work must survive result truncation: render it first, then a
   // bounded tail of closed history (completed and cancelled), most recent