Add per-child all-done and present-today binary sensors

all_done is on exactly when the child owed quests today and owes none
remaining (a zero-quest day stays off so celebrations never fire on
an empty day); present_today mirrors the presence engine's answer
for the HA-local date.

custom_components/nestquest/binary_sensor.py

@@ -0,0 +1,191 @@
+"""Per-child binary sensors (Feature 10, task 4).
+
+Two binary sensors per active child, both reading only the coordinator
+snapshot (the same ChildDaySnapshot the day sensors read):
+
+- ``binary_sensor.nestquest_<child>_all_done`` — ON exactly when the
+  child owes quests today (due today > 0) AND owes none of them any
+  more (remaining today == 0).  A zero-quest day is OFF: the
+  celebration automation must never fire on an empty day (the
+  day-complete event carries the same rule, Feature 10 task 7).
+- ``binary_sensor.nestquest_<child>_present_today`` — ON when the
+  presence engine resolves the child present on the HA-local date
+  (schedules and overrides, D-004 anchor-date arithmetic).
+
+Naming and registry identity follow the day sensors' contract: names
+slug to the documented entity_id shape; unique_ids are built from the
+child's database id, never the display name, so a rename never
+orphans an entity's history.
+"""
+from __future__ import annotations
+
+from collections.abc import Callable, Iterable
+from typing import Any
+
+from homeassistant.components.binary_sensor import BinarySensorEntity
+from homeassistant.config_entries import ConfigEntry
+from homeassistant.core import HomeAssistant
+from homeassistant.helpers.entity import DeviceInfo
+from homeassistant.helpers.update_coordinator import CoordinatorEntity
+
+from .const import DOMAIN
+from .coordinator import ChildDaySnapshot, NestQuestCoordinator
+
+
+class _NestQuestChildBinarySensor(CoordinatorEntity, BinarySensorEntity):
+    """Base for the per-child binary sensors.
+
+    Registry identity is built from the child's database id and never
+    changes; the displayed name and device label re-derive from the
+    child's CURRENT snapshot on every read, so a rename propagates on
+    the next refresh without orphaning history.  A child absent from
+    the latest snapshot (a deactivation; removal is a later task's
+    scope) yields ``None`` states rather than stale values.
+    """
+
+    _name_suffix: str = ""
+
+    def __init__(
+        self,
+        coordinator: NestQuestCoordinator,
+        child: ChildDaySnapshot,
+    ) -> None:
+        super().__init__(coordinator)
+        self._child_id = child.child_id
+        self._fallback_name = child.child_name
+
+    @property
+    def _child(self) -> ChildDaySnapshot | None:
+        """Return the child's current day snapshot, or None."""
+        data = self.coordinator.data
+        if data is None:
+            return None
+        for child in data.children:
+            if child.child_id == self._child_id:
+                return child
+        return None
+
+    def _displayed_child_name(self) -> str:
+        child = self._child
+        return child.child_name if child is not None else self._fallback_name
+
+    @property
+    def name(self) -> str | None:
+        return f"NestQuest {self._displayed_child_name()} {self._name_suffix}"
+
+    @property
+    def device_info(self) -> DeviceInfo:
+        return DeviceInfo(
+            identifiers={(DOMAIN, f"child_{self._child_id}")},
+            name=f"NestQuest {self._displayed_child_name()}",
+            manufacturer="NestQuest",
+        )
+
+    @property
+    def extra_state_attributes(self) -> dict[str, Any] | None:
+        child = self._child
+        if child is None:
+            return None
+        return {
+            "child_id": child.child_id,
+            "child_name": child.child_name,
+        }
+
+
+class NestQuestAllDoneSensor(_NestQuestChildBinarySensor):
+    """ON when the child had quests today and owes none of them."""
+
+    _name_suffix = "all done"
+
+    def __init__(
+        self,
+        coordinator: NestQuestCoordinator,
+        child: ChildDaySnapshot,
+    ) -> None:
+        super().__init__(coordinator, child)
+        self._attr_unique_id = f"{DOMAIN}_child_{child.child_id}_all_done"
+
+    @property
+    def is_on(self) -> bool | None:
+        child = self._child
+        if child is None:
+            return None
+        # Zero-quest days are OFF, not ON: an empty day must never fire
+        # the celebration automation.
+        return child.due_today > 0 and child.remaining_today == 0
+
+
+class NestQuestPresentTodaySensor(_NestQuestChildBinarySensor):
+    """ON when the child is at this house today (presence engine)."""
+
+    _name_suffix = "present today"
+
+    def __init__(
+        self,
+        coordinator: NestQuestCoordinator,
+        child: ChildDaySnapshot,
+    ) -> None:
+        super().__init__(coordinator, child)
+        self._attr_unique_id = f"{DOMAIN}_child_{child.child_id}_present_today"
+
+    @property
+    def is_on(self) -> bool | None:
+        child = self._child
+        if child is None:
+            return None
+        return child.present
+
+
+def _child_binary_sensors(
+    coordinator: NestQuestCoordinator, child: ChildDaySnapshot
+) -> tuple[_NestQuestChildBinarySensor, ...]:
+    """Build the two documented binary sensors for one active child."""
+    return (
+        NestQuestAllDoneSensor(coordinator, child),
+        NestQuestPresentTodaySensor(coordinator, child),
+    )
+
+
+async def async_setup_entry(
+    hass: HomeAssistant,
+    entry: ConfigEntry,
+    async_add_entities: Callable[..., None],
+) -> None:
+    """Create the two binary sensors per active child.
+
+    Entities are created for the snapshot's children at platform
+    setup; a coordinator listener adds sensors for children that first
+    appear on a later refresh (the day sensors' same pattern, so a new
+    child's whole entity set lands together).  Deactivated children
+    are NOT removed here — removal is a later task's scope.
+    """
+    coordinator = entry.runtime_data.coordinator
+    known_child_ids: set[int] = set()
+
+    def _add_new_children(children: Iterable[ChildDaySnapshot]) -> None:
+        new_children = [
+            child
+            for child in children
+            if child.child_id not in known_child_ids
+        ]
+        if not new_children:
+            return
+        known_child_ids.update(child.child_id for child in new_children)
+        async_add_entities(
+            [
+                sensor
+                for child in new_children
+                for sensor in _child_binary_sensors(coordinator, child)
+            ]
+        )
+
+    data = coordinator.data
+    if data is not None:
+        _add_new_children(data.children)
+
+    def _handle_coordinator_update() -> None:
+        data = coordinator.data
+        if data is not None:
+            _add_new_children(data.children)
+
+    coordinator.async_add_listener(_handle_coordinator_update)