One solution to this if you're using Shellies to provide your "turn a dumb light switch into a smart light switch" is the scripting it has on offer.
I have 100% Zigbee lights, and each lighting circuit has a Shelly Plus 1 with the relay in "detached" mode (so the shelly will sense the light switch changing from open to closed and send a command to HA to turn on the lights via Zigbee). Most (all?) smart bulbs have a setting for "what do I do when power is restored" and you can set it so that they come on when power is restored.
You can then create a script that uses the MQTT HomeAssistant up/down topic and if HA is down, when the switch changes position operate the relay.
It's not perfect - if you have a powercut during the night all of your lights will come on when power is restored.
I have 100% Zigbee lights, and each lighting circuit has a Shelly Plus 1 with the relay in "detached" mode (so the shelly will sense the light switch changing from open to closed and send a command to HA to turn on the lights via Zigbee). Most (all?) smart bulbs have a setting for "what do I do when power is restored" and you can set it so that they come on when power is restored.
You can then create a script that uses the MQTT HomeAssistant up/down topic and if HA is down, when the switch changes position operate the relay.
It's not perfect - if you have a powercut during the night all of your lights will come on when power is restored.