Scaffold repo: infra docker-compose, service layout, README

Sets up the microservice home-automation platform skeleton: docker-compose
for mosquitto/postgres/clickhouse/redis/rabbitmq, per-service README stubs
describing responsibilities, and top-level README with architecture/stack.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

services/esp32-emulator/README.md

@@ -0,0 +1,11 @@
+# esp32-emulator (Go)
+
+Status: not implemented yet.
+
+Responsibility:
+- Stand in for real ESP32 hardware during MVP development.
+- Publish plausible telemetry (temperature/humidity/etc.) to
+  `devices/{device_id}/telemetry` over MQTT on an interval.
+- Subscribe to `devices/{device_id}/commands` and reply on
+  `devices/{device_id}/ack`, so device-control-service has something real
+  to talk to.