fix(atlas): replace permanent failure lockout with 5-minute backoff

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

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

src/hooks/atlas/event-handler.ts

@@ -10,6 +10,7 @@ import { getLastAgentFromSession } from "./session-last-agent"
 import type { AtlasHookOptions, SessionState } from "./types"
 
 const CONTINUATION_COOLDOWN_MS = 5000
+const FAILURE_BACKOFF_MS = 5 * 60 * 1000
 
 export function createAtlasEventHandler(input: {
   ctx: PluginInput
@@ -53,6 +54,7 @@ export function createAtlasEventHandler(input: {
       }
 
       const state = getState(sessionID)
+      const now = Date.now()
 
       if (state.lastEventWasAbortError) {
         state.lastEventWasAbortError = false
@@ -61,11 +63,18 @@ export function createAtlasEventHandler(input: {
       }
 
       if (state.promptFailureCount >= 2) {
-        log(`[${HOOK_NAME}] Skipped: continuation disabled after repeated prompt failures`, {
-          sessionID,
-          promptFailureCount: state.promptFailureCount,
-        })
-        return
+        const timeSinceLastFailure = state.lastFailureAt !== undefined ? now - state.lastFailureAt : Number.POSITIVE_INFINITY
+        if (timeSinceLastFailure < FAILURE_BACKOFF_MS) {
+          log(`[${HOOK_NAME}] Skipped: continuation in backoff after repeated failures`, {
+            sessionID,
+            promptFailureCount: state.promptFailureCount,
+            backoffRemaining: FAILURE_BACKOFF_MS - timeSinceLastFailure,
+          })
+          return
+        }
+
+        state.promptFailureCount = 0
+        state.lastFailureAt = undefined
       }
 
       const backgroundManager = options?.backgroundManager
@@ -111,7 +120,6 @@ export function createAtlasEventHandler(input: {
         return
       }
 
-      const now = Date.now()
       if (state.lastContinuationInjectedAt && now - state.lastContinuationInjectedAt < CONTINUATION_COOLDOWN_MS) {
         log(`[${HOOK_NAME}] Skipped: continuation cooldown active`, {
           sessionID,