feat: youtube_transcribe blocks with polling, interruptible with background retrieve

- youtube_transcribe now polls until transcript is ready (waits estimated_seconds - 2s, min 2s)
- Times out after 10 minutes of polling
- When user interrupts, polling continues in background with youtube_transcribe_<uuid> job ID
- BackgroundTranscriptStore holds polling jobs, retrieve tool resolves them
- ToolCallDisplay shows 'interrupted' badge (blue) when result contains [USER INTERRUPT]
- Applies to all interruptible tools: run_shell, youtube_transcribe, retrieve

1 files changed, 1 insertions, 1 deletions

diff --git a/packages/core/src/index.ts b/packages/core/src/index.ts
index b092fe2..8d5db16 100644
--- a/packages/core/src/index.ts
+++ b/packages/core/src/index.ts
@@ -57,6 +57,6 @@ export { createSummonTool, type SummonCallbacks } from "./tools/summon.js";
 export { createTaskListTool, TaskList } from "./tools/task-list.js";
 export { createWebSearchTool } from "./tools/web-search.js";
 export { createWriteFileTool } from "./tools/write-file.js";
-export { createYoutubeTranscribeTool } from "./tools/youtube-transcribe.js";
+export { BackgroundTranscriptStore, createYoutubeTranscribeTool } from "./tools/youtube-transcribe.js";
 // Types & Permissions
 export * from "./types/index.js";