v9.2.0

Changed

• CLI formatting stacks merged; Rich is the sole human renderer
  (#100 <https://github.com/eman/nwp500-python/issues/100>_): a new
  src/nwp500/cli/presentation.py owns all data-shaping for CLI output
  (field selection, labels, units, ordering, value formatting and energy
  aggregation) as presentation-neutral structures. Because the CLI
  hard-requires rich (there is no plain-text fallback), the redundant
  plain-text human renderer and the Rich-vs-plain fallback machinery were
  removed: rich_output.py no longer contains _should_use_rich,
  _rich_available, the NWP500_NO_RICH toggle, or any
  _print_*_plain methods, and now renders the neutral structures
  (including the energy TOTAL SUMMARY) exclusively with Rich, consuming
  the presentation dataclasses directly instead of dict adapters.
  output_formatters.py keeps only JSON/CSV rendering plus thin
  human-output dispatch. Net CLI code drops from ~2088 to ~1838 lines with a
  single data-shaping layer and a single human renderer. Non-energy output
  is byte-for-byte unchanged (verified by golden capture and the existing
  CLI tests); energy output now renders a summary table plus a breakdown
  table entirely in Rich rather than printing plain text and a Rich table.

• mqtt/client.py slimmed toward a thin façade (#99 <https://github.com/eman/nwp500-python/issues/99>_): the ~40 device
  control command proxies and the typed subscribe_*/unsubscribe_*
  device-subscription proxies were moved out of NavienMqttClient into
  two focused mixins, DeviceControlCommandsMixin
  (mqtt/_control_commands.py) and DeviceSubscriptionsMixin
  (mqtt/_device_subscriptions.py). NavienMqttClient now inherits
  both, so its public API is unchanged, while mqtt/client.py shrinks
  from ~1572 to ~1196 lines and reads more clearly as connection
  orchestration plus a public façade. No behavior change.

• Event system relationship clarified and de-duplicated (#102 <https://github.com/eman/nwp500-python/issues/102>_): events.py and
  mqtt_events.py are not two competing event mechanisms.
  EventEmitter (events.py) is the sole delivery mechanism, while
  mqtt_events.py provides the event-name registry
  (MqttClientEvents) and the typed dataclass payloads it carries.
  Internal emit call sites in mqtt/state_tracker.py,
  mqtt/client.py and mqtt/subscriptions.py now reference the
  MqttClientEvents constants instead of duplicating the raw event-name
  strings, so each event name is defined in exactly one place. Module
  docstrings and the event-system reference docs were updated to document
  the relationship, and typed-payload delivery is now covered by tests.

• awscrt types wrapped out of public MQTT signatures (#101 <https://github.com/eman/nwp500-python/issues/101>_): the library no
  longer exposes awscrt SDK types on its own public/semi-public API
  surface. A library-owned nwp500.mqtt.QoS IntEnum (also exported
  as nwp500.QoS) now replaces awscrt.mqtt.QoS on the publish
  and subscribe methods of NavienMqttClient, MqttConnection
  and MqttSubscriptionManager, on MqttCommandQueue.enqueue and on
  the QueuedCommand dataclass. awscrt.mqtt.Connection handles are
  typed behind the MqttConnectionHandle alias, and translation to/from
  awscrt happens only at the connection-layer boundary
  (nwp500/mqtt/types.py). NavienMqttClient.publish now wraps
  otherwise-uncaught AwsCrtError in MqttPublishError so awscrt
  exceptions no longer leak out of the public boundary.

  .. code-block:: python

  OLD

  from awscrt import mqtt
  await client.publish(topic, payload, qos=mqtt.QoS.AT_LEAST_ONCE)

  NEW

  from nwp500 import QoS
  await client.publish(topic, payload, qos=QoS.AT_LEAST_ONCE)

Fixed

• MQTT ack futures now consumed on abandonment (#97 <https://github.com/eman/nwp500-python/issues/97>_): _await_ack()
  in mqtt/connection.py and the inline subscribe/unsubscribe
  acknowledgement waits in mqtt/subscriptions.py shield the AWS CRT
  future so a timeout or cancellation doesn't propagate into the SDK
  future. Previously, if the shielded future later completed with an
  exception (e.g. AwsCrtError from clean-session cancellation during
  reconnect) after the awaiting task had already given up, nobody
  retrieved that exception, and asyncio logged a "Future exception was
  never retrieved" warning at garbage-collection time. A done callback
  is now attached whenever a wait is abandoned so the eventual
  result/exception is always retrieved and logged at debug level
  instead of leaking as an unhandled asyncio warning.

Documentation

• Unit-system preference is a deliberate process-wide global (#103 <https://github.com/eman/nwp500-python/issues/103>_): clarified and
  locked in that the preference in nwp500.unit_system is an intentional
  process-wide module-level global rather than a
  contextvars.ContextVar. A context-local value silently reverted to
  auto-detect for real-time data because MQTT message handling runs in tasks
  scheduled from AWS CRT callback threads whose context never inherits from
  the application task. Added prominent docstring notes to the affected
  models (DeviceStatus, DeviceFeature, ReservationEntry,
  WeeklyReservationEntry, and TOUPeriod) explaining that unit-aware
  computed fields read the preference at access time and share it across all
  async tasks and threads. This is a non-breaking documentation and test
  change; no API changes.

Added

• Tests for process-wide unit-system semantics (#103 <https://github.com/eman/nwp500-python/issues/103>_): new
  tests/test_unit_system_process_wide.py verifies that setting the global
  preference affects already-constructed model instances at access time and
  that the preference is visible across async tasks and threads.