Revert "revert: roll back v12.3.3 (Issue Blowout 2026)"

This reverts commit bfc7de377a.

src/cli/handlers/summarize.ts

@@ -84,16 +84,24 @@ export const summarizeHandler: EventHandler = {
     const platformSource = normalizePlatformSource(input.platform);
 
     // 1. Queue summarize request — worker returns immediately with { status: 'queued' }
-    const response = await workerHttpRequest('/api/sessions/summarize', {
-      method: 'POST',
-      headers: { 'Content-Type': 'application/json' },
-      body: JSON.stringify({
-        contentSessionId: sessionId,
-        last_assistant_message: lastAssistantMessage,
-        platformSource
-      }),
-      timeoutMs: SUMMARIZE_TIMEOUT_MS
-    });
+    let response: Response;
+    try {
+      response = await workerHttpRequest('/api/sessions/summarize', {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({
+          contentSessionId: sessionId,
+          last_assistant_message: lastAssistantMessage,
+          platformSource
+        }),
+        timeoutMs: SUMMARIZE_TIMEOUT_MS
+      });
+    } catch (err) {
+      // Network error, worker crash, or timeout — exit gracefully instead of
+      // bubbling to hook runner which exits code 2 and blocks session exit (#1901)
+      logger.warn('HOOK', `Stop hook: summarize request failed: ${err instanceof Error ? err.message : err}`);
+      return { continue: true, suppressOutput: true, exitCode: HOOK_EXIT_CODES.SUCCESS };
+    }
 
     if (!response.ok) {
       return { continue: true, suppressOutput: true };