ge-0y6: telemetry receiver prototype

[SorraTheOrc]

Summary

• Add lightweight telemetry receiver at server/telemetry/receiver.js that accepts POSTed JSON and persists director_decision events to server/telemetry/events.ndjson.

Changes

• server/telemetry/receiver.js — HTTP POST handler, accepts director_decision events and appends NDJSON lines
• server/telemetry/README.md — run + curl examples

Closes bd#ge-0y6

How to verify locally:

1. Start the receiver: PORT=4005 node server/telemetry/receiver.js
2. Send a valid event: curl -X POST -H 'Content-Type: application/json' -d '{type:director_decision,decision:accept}' http://localhost:4005/
3. Confirm server/telemetry/events.ndjson contains a JSON line with director_decision.