feat(smartir): power consumption feedback and retries

[jmcaracoche]

Problem

• Binary power_sensor only works when the monitor exposes strict on/off. Many setups use a watt sensor on a plug or Zigbee energy reporting.
• IR can be missed; a single send may not match physical load until retried.

What this adds

• Optional power_consumption_sensor (+ threshold + W/kW handling) on climate, fan, light, and media_player when power_sensor is not set (binary wins if both).
• Shared custom_components/smartir/power_feedback.py for watt parsing, threshold mapping, and exponential-backoff retry after sends when feedback mismatches desired on/off (configurable retry count and delays).
• Climate: optimistic UI (write HA state before awaiting IR/retry) and defer consumption-driven _apply_effective_power while send+retries run so the card does not flip off while power is still ramping or IR is retried.
• manifest.json updater files includes power_feedback.py for HACS-style updates.

Docs

• Configuration tables aligned with CLIMATE style; consumption + retry examples for all platforms.

Benefit

• Keeps entity state aligned with real device load using common energy sensors.
• Reduces stuck UI vs reality after missed IR via bounded retries.