fix(plugin): verify event hook compatibility with v1.4.0

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

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

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

@@ -150,14 +150,21 @@ export async function handleSessionIdle(args: {
 
   let resolvedInfo: ResolvedMessageInfo | undefined
   let encounteredCompaction = false
+  let latestMessageWasCompaction = false
   try {
     const messageInfoResult = await resolveLatestMessageInfo(ctx, sessionID, prefetchedMessages)
     resolvedInfo = messageInfoResult.resolvedInfo
     encounteredCompaction = messageInfoResult.encounteredCompaction
+    latestMessageWasCompaction = messageInfoResult.latestMessageWasCompaction
   } catch (error) {
     log(`[${HOOK_NAME}] Failed to fetch messages for agent check`, { sessionID, error: String(error) })
   }
 
+  if (latestMessageWasCompaction) {
+    log(`[${HOOK_NAME}] Skipped: latest message is a compaction marker`, { sessionID })
+    return
+  }
+
   const sessionAgent = getSessionAgent(sessionID)
   if (!resolvedInfo?.agent && sessionAgent) {
     resolvedInfo = { ...resolvedInfo, agent: sessionAgent }