feat(pipeline): add multi-agent pipeline engine, sidechat auto-provisioning, and CDP event isolation

- Add bin/pipeline_engine.py for persistent multi-agent execution tracking in pipelines.json
- Add jobs/pipe-demo-step1.json and jobs/pipe-demo-step2.json demo pipeline definitions
- Use ev1 in bin/muse-chat-api.py across send/messages/compose/create to avoid dropping return values on CDP event chatter
- Support Muse unconfirmed signup error handling in bin/muse-signin.py
- Add runtime state and telemetry files to .gitignore
- Track dynamic pipe sidechat mappings in job-sidechats.json

job-sidechats.json

@@ -32,5 +32,15 @@
     "thread_uuid": "dc2288ef-3fe1-4b12-bf31-08c482398c0f",
     "agent": "646",
     "created_at": "2026-10-04T16:50:35.478877+00:00"
+  },
+  "pipe-caddc7": {
+    "thread_uuid": "9726b713-32a7-4df6-8582-32f2af8dd95a",
+    "agent": "opm",
+    "created_at": "2026-10-04T16:53:04.977475+00:00"
+  },
+  "pipe-1b4579": {
+    "thread_uuid": "bf7bf3e1-3ee8-4816-9b66-b77b34387986",
+    "agent": "opm",
+    "created_at": "2026-10-04T16:53:54.998468+00:00"
   }
 }