feat: initial myprimal MQTT bridge service

Dynamic MySolem/MyIndygo IoT bridge with MQTT, Home Assistant
autodiscovery, and Homebridge EasyMQTT compatibility.

- Device discovery via MySolem API on startup (all modules/inputs/outputs)
- Configurable poll engine (fast/normal/slow buckets, per-input overrides)
- MQTT retained state publishing + HA autodiscovery payloads
- Unified manual command routing (linesControl vs sendManualModuleCommand)
- Runtime config via MQTT $config/set, persisted to config.json
- Expression override system (API-provided > hardcoded > passthrough)
- Minimal REST API: /health, /state, /control, /rediscover
- Docker deployment (Dockerfile + docker-compose.yml)
- 38 unit tests

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.env.example

@@ -0,0 +1,22 @@
+# MySolem credentials
+SOLEM_EMAIL=your@email.com
+SOLEM_PASSWORD=yourpassword
+SOLEM_BASE=https://qualif.mysolem.com
+INDYGO_BASE=https://qualif.myindygo.com
+
+# Optional: override user ID (default from CLAUDE.md)
+# SOLEM_USER_ID=5de53bca7ed4c45c2cfe067f
+
+# MQTT broker
+MQTT_URL=mqtt://localhost:1883
+MQTT_USERNAME=
+MQTT_PASSWORD=
+MQTT_TOPIC_PREFIX=myprimal
+
+# REST API port
+PORT=3001
+
+# Poll intervals (seconds) — also tunable at runtime via MQTT $config/set
+POLL_FAST=60
+POLL_NORMAL=300
+POLL_SLOW=900