feat: notebook 04 — JetStream a fondo + simulador de rendimiento interactivo

JetStream: anatomia de streams (storage/retention/limits), consumers pull durables
con ack y cursor, dedup por Nats-Msg-Id, retencion workqueue, deliver policies.
Simulador: boton ipywidgets que lanza 1 publisher -> N subscribers con miles de
mensajes y grafica en movimiento (acumulado + throughput instantaneo).

.jupyter/collaboration_sessions.json

@@ -6,7 +6,17 @@
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     "version": "2.4.0",
-    "created_at": "2026-06-03T17:46:15.674895+00:00",
+    "created_at": "2026-06-03T19:04:11.779086+00:00",
+    "document_version": "2.0.0"
+  },
+  "6a0e97d4-34d4-44f3-8a47-243934257256": {
+    "version": "2.4.0",
+    "created_at": "2026-06-03T19:16:39.520669+00:00",
+    "document_version": "2.0.0"
+  },
+  "bc0d99c9-d3bf-49c2-a87a-b38af47d1bff": {
+    "version": "2.4.0",
+    "created_at": "2026-06-03T19:18:34.134263+00:00",
     "document_version": "2.0.0"
   }
 }