v1.12.2 — Availability side-effect cleanup + unreachable-ignore removal

Changed

• available property is now side-effect free. Device online/offline transitions were logged inside the property, which Home Assistant reads every time a UI client reads an entity attribute — so the log message and internal state mutation fired far more often than the actual transition. The transition-logging moved to _handle_coordinator_update, which runs exactly once per coordinator update. Applies to both GardenaEntity and AutomowerEntity.
• # type: ignore[unreachable] guards removed across 17 files. The pattern if coordinator.data is None: return # type: ignore[unreachable] lied to mypy — DataUpdateCoordinator.data is genuinely None during async_config_entry_first_refresh. Replaced with the equivalent truthy check if not coordinator.data: return (and the _device property uses (self.coordinator.data or {}).get(…)), which mypy understands without any ignores.
• MQTT command-handler tasks now carry a name. Inbound MQTT commands dispatched as hass.async_create_task(…) now include name=f"gardena_mqtt_command_{device_id}" for easier tracing.
• WebSocket-connect lock cleaned up. The .locked() pre-check (TOCTOU-prone) was replaced with an unconditional acquire plus a self._ws_connected double-check under the lock. Strictly race-free; behaviour identical.
• Config-flow error tuple precomputed. _GARDENA_ERROR_TYPES = tuple(_GARDENA_ERROR_MAP) at module level replaces three per-call tuple(_GARDENA_ERROR_MAP) rebuilds.

Library

• No changes — still pins aiogardenasmart==0.1.9.