fix(hooks): guard stale idle prompts

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

@@ -21,6 +21,7 @@ import {
   getAgentConfigKey,
   normalizeAgentForPromptKey,
 } from "../../shared/agent-display-names"
+import { isSessionActive } from "../shared/session-idle-settle"
 
 import {
   CONTINUATION_PROMPT,
@@ -165,6 +166,11 @@ ${todoList}`
     return
   }
 
+  if (await isSessionActive(ctx.client, sessionID)) {
+    log(`[${HOOK_NAME}] Skipped injection: session is active before prompt`, { sessionID })
+    return
+  }
+
   if (injectionState) {
     injectionState.inFlight = true
   }