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/ingest-service/README.md

@@ -0,0 +1,13 @@
+# ingest-service (Go)
+
+Status: not implemented yet.
+
+Responsibility:
+- Subscribe to MQTT topics `devices/{device_id}/telemetry`.
+- Validate/parse payload (device_id, sensor_type, value, timestamp).
+- Batch-write raw readings into ClickHouse `telemetry` table.
+- Publish a "new reading" event to RabbitMQ for rule-engine-service.
+
+Not this service's job: interpreting what a sensor reading *means* (thresholds,
+actions) — that belongs to rule-engine-service. This service only ingests and
+stores.