Fix INA2xx MQTT energy restore handling

[KrX3D]

Motivation

• Prevent double-counting and incorrect resets when retained MQTT energy state is merged after boot or reconnects by deferring restore until time is synced and validating day/month boundaries.

Description

• Added a MqttRestoreData buffer and flags (mqttRestorePending, mqttStateRestored) to collect retained MQTT energy payloads without immediately merging them (usermods/ina2xx_v2/ina2xx_v2.h).
• Implemented isTimeValid() and applyMqttRestoreIfReady() to defer applying the retained state until localTime is valid and to only merge daily/monthly values when the restored reset day/month matches the device current day/month (usermods/ina2xx_v2/ina2xx_v2.cpp).
• Changed onMqttMessage() to populate the restore buffer instead of directly adding values to the running totals, then trigger a safe apply attempt; added a call to applyMqttRestoreIfReady() from loop() so restore is applied as soon as conditions allow.
• Centralized time validation in updateEnergy() to use isTimeValid() and added logging to help diagnose restore and merge decisions.

Testing

• No automated tests were run against these changes during this update.
• Static compile and basic code-path checks were considered during editing (manual review only).

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Codex Task