Per-entity availability, deferred discovery publish, suggested precision

- Add HAAvailabilityConfig for per-entity availability_topic and payloads
- Defer discovery until MQTT connected; publish availability after discovery
- HASensor/HANumber: optional suggested_display_precision in discovery
- HASerializer/HADictionary: extend for new keys; update device types and mocks
- Docs and examples reflect availability and precision usage
- Tests updated for discovery and availability behavior
- Ignore .cursor/ in repo root

examples/advanced-availability/advanced-availability.ino

@@ -29,10 +29,19 @@ void setup() {
     // set device's details (optional)
     device.setName("Arduino");
     device.setSoftwareVersion("1.0.0");
+    mqtt.setOriginSupportUrl("https://example.com/device-help");
 
     sensor.setCurrentState(lastInputState); // optional
     sensor.setName("Door sensor"); // optional
     sensor.setDeviceClass("door"); // optional
+    sensor.setPayloadAvailable("ready");
+    sensor.setPayloadNotAvailable("lost");
+
+    // Optional multi-topic discovery metadata for external health sources.
+    // Runtime availability publishing still uses sensor.setAvailability(...).
+    // sensor.setAvailabilityMode("all");
+    // sensor.addAvailabilityEntry("bridge/status");
+    // sensor.addAvailabilityEntry("sensor/health", "{{ value_json.state }}");
 
     // This method enables availability for all device types registered on the device.
     // For example, if you have 5 sensors on the same device, you can enable

examples/button/button.ino

@@ -33,6 +33,8 @@ void setup() {
     // optional properties
     buttonA.setIcon("mdi:fire");
     buttonA.setName("Click me A");
+    // buttonA.setPayloadPress("PRESS_A");
+    // buttonA.setCommandTemplate("{{ value_json.command }}");
     buttonB.setIcon("mdi:home");
     buttonB.setName("Click me B");
 

examples/led-switch/led-switch.ino

@@ -33,6 +33,11 @@ void setup() {
     // set icon (optional)
     led.setIcon("mdi:lightbulb");
     led.setName("My LED");
+    // led.setPayloadOn("ENABLE");
+    // led.setPayloadOff("DISABLE");
+    // led.setStateOn("running");
+    // led.setStateOff("stopped");
+    // led.setCommandTemplate("{{ value_json.command }}");
 
     // handle switch state
     led.onCommand(onSwitchCommand);

examples/number/number.ino

@@ -52,6 +52,9 @@ void setup() {
     // number.setStep(0.5f); // minimum step: 0.001f
     // number.setMode(HANumber::ModeBox);
     // number.setMode(HANumber::ModeSlider);
+    // number.setValueTemplate("{{ value_json.level }}");
+    // number.setPayloadReset("RESET");
+    // number.setCommandTemplate("{{ value | float | round(1) }}");
 
     // You can set retain flag for the HA commands
     // number.setRetain(true);

examples/sensor-analog/sensor-analog.ino

@@ -30,6 +30,8 @@ void setup() {
     analogSensor.setIcon("mdi:home");
     analogSensor.setName("Analog voltage");
     analogSensor.setUnitOfMeasurement("V");
+    analogSensor.setSuggestedDisplayPrecision(2);
+    // analogSensor.setValueTemplate("{{ value_json.voltage }}");
 
     mqtt.begin(BROKER_ADDR);
 }

examples/sensor/sensor.ino

@@ -23,6 +23,10 @@ void setup() {
     // configure sensor (optional)
     valve.setIcon("mdi:home");
     valve.setName("Water valve");
+    // valve.setValueTemplate("{{ value_json.state }}");
+    // valve.setDeviceClass("enum");
+    // valve.setOptions("open;opening;closed");
+    // valve.setDefaultEntityId("sensor.water_valve");
 
     mqtt.begin(BROKER_ADDR);
 }