fix: jupyter_exec usa run_in_executor para execute_cell

Evita bloquear el event loop asyncio ejecutando execute_cell (operación
síncrona con websocket) en un thread executor.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

python/functions/notebook/jupyter_exec.py

@@ -8,6 +8,7 @@ Tres modos de ejecucion:
 
 import asyncio
 import json
+from functools import partial
 from typing import Any
 from urllib.error import URLError
 from urllib.request import Request, urlopen
@@ -106,7 +107,10 @@ async def _async_append_execute(
 
         with KernelClient(server_url=server_url, token=token, kernel_id=kernel_id) as kernel:
             cell_index = nb.add_code_cell(code)
-            result = nb.execute_cell(cell_index, kernel)
+            loop = asyncio.get_event_loop()
+            result = await loop.run_in_executor(
+                None, partial(nb.execute_cell, cell_index, kernel),
+            )
 
         # Let Y.js propagate changes to other clients (browser)
         await asyncio.sleep(2)
@@ -138,7 +142,10 @@ async def _async_execute_cell(
         await nb.wait_until_synced()
 
         with KernelClient(server_url=server_url, token=token, kernel_id=kernel_id) as kernel:
-            result = nb.execute_cell(cell_index, kernel)
+            loop = asyncio.get_event_loop()
+            result = await loop.run_in_executor(
+                None, partial(nb.execute_cell, cell_index, kernel),
+            )
 
         await asyncio.sleep(2)