canbus: furnace + water-heater status sensors (running + DSI fault)

Decode node 89 (furnace) read-only: Furnace Running (page-3 b0 bit0) and
Furnace DSI Fault (b0 bit5), same type-0x1E DSI encoding as the water
heater. The furnace is thermostat-controlled, not a Lippert load — it
sits on the bus only to report ignition state. Captures only ever showed
0x80 (off), so the 0x81 running / 0xA0 fault bytes are inferred by
parallel to node 95; confirm on the first real burn.

Add Water Heater Heating (node 95 page-3 x[3] bit7 = burner actively
firing) — distinct from the on/off switch, which only reflects "enabled".

Carry all three through the MQTT bridge to home HA, add the furnace
DSI-fault Octavia alert mirroring the water heater, and update the README
node map (89 was "unknown switched load"). Campsite + home Camper
dashboards updated live.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

canbus/ha/mqtt_bridge_onecontrol.yaml

@@ -165,6 +165,43 @@ automation:
              "device_class": "problem",
              "availability_topic": "campsite/onecontrol/availability",
              "device": {"identifiers": ["campsite_onecontrol"]}}
+      - action: mqtt.publish
+        data:
+          topic: "homeassistant/binary_sensor/campsite/furnace_dsi_fault/config"
+          retain: true
+          payload: >-
+            {"name": "Furnace DSI Fault",
+             "unique_id": "campsite_furnace_dsi_fault",
+             "state_topic": "campsite/binary_sensor/furnace_dsi_fault/state",
+             "payload_on": "ON", "payload_off": "OFF",
+             "device_class": "problem",
+             "availability_topic": "campsite/onecontrol/availability",
+             "device": {"identifiers": ["campsite_onecontrol"]}}
+      # Running/heating status binary sensors
+      - action: mqtt.publish
+        data:
+          topic: "homeassistant/binary_sensor/campsite/water_heater_heating/config"
+          retain: true
+          payload: >-
+            {"name": "Water Heater Heating",
+             "unique_id": "campsite_water_heater_heating",
+             "state_topic": "campsite/binary_sensor/water_heater_heating/state",
+             "payload_on": "ON", "payload_off": "OFF",
+             "device_class": "running",
+             "availability_topic": "campsite/onecontrol/availability",
+             "device": {"identifiers": ["campsite_onecontrol"]}}
+      - action: mqtt.publish
+        data:
+          topic: "homeassistant/binary_sensor/campsite/furnace_running/config"
+          retain: true
+          payload: >-
+            {"name": "Furnace Running",
+             "unique_id": "campsite_furnace_running",
+             "state_topic": "campsite/binary_sensor/furnace_running/state",
+             "payload_on": "ON", "payload_off": "OFF",
+             "device_class": "running",
+             "availability_topic": "campsite/onecontrol/availability",
+             "device": {"identifiers": ["campsite_onecontrol"]}}
       # Awning
       - action: mqtt.publish
         data:
@@ -230,6 +267,21 @@ automation:
           topic: "campsite/binary_sensor/onecontrol_system_fault/state"
           retain: true
           payload: "{{ 'ON' if is_state('binary_sensor.onecontrol_can_onecontrol_system_fault', 'on') else 'OFF' }}"
+      - action: mqtt.publish
+        data:
+          topic: "campsite/binary_sensor/furnace_dsi_fault/state"
+          retain: true
+          payload: "{{ 'ON' if is_state('binary_sensor.onecontrol_can_furnace_dsi_fault', 'on') else 'OFF' }}"
+      - action: mqtt.publish
+        data:
+          topic: "campsite/binary_sensor/water_heater_heating/state"
+          retain: true
+          payload: "{{ 'ON' if is_state('binary_sensor.onecontrol_can_water_heater_heating', 'on') else 'OFF' }}"
+      - action: mqtt.publish
+        data:
+          topic: "campsite/binary_sensor/furnace_running/state"
+          retain: true
+          payload: "{{ 'ON' if is_state('binary_sensor.onecontrol_can_furnace_running', 'on') else 'OFF' }}"
       - action: mqtt.publish
         data:
           topic: "campsite/cover/awning/state"
@@ -300,6 +352,9 @@ automation:
         entity_id:
           - binary_sensor.onecontrol_can_water_heater_dsi_fault
           - binary_sensor.onecontrol_can_onecontrol_system_fault
+          - binary_sensor.onecontrol_can_furnace_dsi_fault
+          - binary_sensor.onecontrol_can_water_heater_heating
+          - binary_sensor.onecontrol_can_furnace_running
     conditions:
       - condition: template
         value_template: "{{ trigger.to_state.state in ['on', 'off'] }}"