fix(todo-continuation-enforcer): stop idle continuation after repeated stagnation

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-opencode)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

src/hooks/todo-continuation-enforcer/idle-event.ts

@@ -16,6 +16,7 @@ import {
 } from "./constants"
 import { isLastAssistantMessageAborted } from "./abort-detection"
 import { hasUnansweredQuestion } from "./pending-question-detection"
+import { shouldStopForStagnation } from "./stagnation-detection"
 import { getIncompleteCount } from "./todo"
 import type { MessageInfo, ResolvedMessageInfo, Todo } from "./types"
 import type { SessionStateStore } from "./session-state"
@@ -93,12 +94,14 @@ export async function handleSessionIdle(args: {
   }
 
   if (!todos || todos.length === 0) {
+    sessionStateStore.resetContinuationProgress(sessionID)
     log(`[${HOOK_NAME}] No todos`, { sessionID })
     return
   }
 
   const incompleteCount = getIncompleteCount(todos)
   if (incompleteCount === 0) {
+    sessionStateStore.resetContinuationProgress(sessionID)
     log(`[${HOOK_NAME}] All todos complete`, { sessionID, total: todos.length })
     return
   }
@@ -183,6 +186,11 @@ export async function handleSessionIdle(args: {
     return
   }
 
+  const progressUpdate = sessionStateStore.trackContinuationProgress(sessionID, incompleteCount)
+  if (shouldStopForStagnation({ sessionID, incompleteCount, progressUpdate })) {
+    return
+  }
+
   startCountdown({
     ctx,
     sessionID,

src/hooks/todo-continuation-enforcer/todo-continuation-enforcer.test.ts

@@ -8,6 +8,7 @@ import {
   CONTINUATION_COOLDOWN_MS,
   FAILURE_RESET_WINDOW_MS,
   MAX_CONSECUTIVE_FAILURES,
+  MAX_STAGNATION_COUNT,
 } from "./constants"
 
 type TimerCallback = (...args: any[]) => void
@@ -626,6 +627,21 @@ describe("todo-continuation-enforcer", () => {
     const sessionID = "main-max-consecutive-failures"
     setMainSession(sessionID)
     const mockInput = createMockPluginInput()
+    const incompleteCounts = [5, 4, 5, 4, 5, 4]
+    let todoCallCount = 0
+    mockInput.client.session.todo = async () => {
+      const countIndex = Math.min(Math.floor(todoCallCount / 2), incompleteCounts.length - 1)
+      const incompleteCount = incompleteCounts[countIndex] ?? incompleteCounts[incompleteCounts.length - 1] ?? 1
+      todoCallCount += 1
+      return {
+        data: Array.from({ length: incompleteCount }, (_, index) => ({
+          id: String(index + 1),
+          content: `Task ${index + 1}`,
+          status: "pending",
+          priority: "high",
+        })),
+      }
+    }
     mockInput.client.session.promptAsync = async (opts: PromptRequestOptions) => {
       promptCalls.push({
         sessionID: opts.path.id,
@@ -657,6 +673,21 @@ describe("todo-continuation-enforcer", () => {
     const sessionID = "main-recovery-after-max-failures"
     setMainSession(sessionID)
     const mockInput = createMockPluginInput()
+    const incompleteCounts = [5, 4, 5, 4, 5, 4, 5]
+    let todoCallCount = 0
+    mockInput.client.session.todo = async () => {
+      const countIndex = Math.min(Math.floor(todoCallCount / 2), incompleteCounts.length - 1)
+      const incompleteCount = incompleteCounts[countIndex] ?? incompleteCounts[incompleteCounts.length - 1] ?? 1
+      todoCallCount += 1
+      return {
+        data: Array.from({ length: incompleteCount }, (_, index) => ({
+          id: String(index + 1),
+          content: `Task ${index + 1}`,
+          status: "pending",
+          priority: "high",
+        })),
+      }
+    }
     mockInput.client.session.promptAsync = async (opts: PromptRequestOptions) => {
       promptCalls.push({
         sessionID: opts.path.id,
@@ -753,7 +784,7 @@ describe("todo-continuation-enforcer", () => {
     expect(promptCalls).toHaveLength(3)
   }, { timeout: 30000 })
 
-  test("should keep injecting even when todos remain unchanged across cycles", async () => {
+  test("should stop injecting after max stagnation cycles when todos remain unchanged across cycles", async () => {
     //#given
     const sessionID = "main-no-stagnation-cap"
     setMainSession(sessionID)
@@ -784,8 +815,8 @@ describe("todo-continuation-enforcer", () => {
     await hook.handler({ event: { type: "session.idle", properties: { sessionID } } })
     await fakeTimers.advanceBy(2500, true)
 
-    //#then — all 5 injections should fire (no stagnation cap)
-    expect(promptCalls).toHaveLength(5)
+    // then
+    expect(promptCalls).toHaveLength(MAX_STAGNATION_COUNT)
   }, { timeout: 60000 })
 
   test("should skip idle handling while injection is in flight", async () => {