Enable to configure Wifi with both STA and AP modes for house external services

Describe the problem you have/What new integration you would like

For a private family house, it may be relevant to have a private LAN with Internet connexion. Then it'a better for privacy to use all home automation devices in DIY mode. But I see two usages for other people (not the family) with their phone without allowing to access the private LAN. This is at the interface with the outside world

Please describe your use case for this integration and alternatives you've tried:

delivering to selected people (friends, delivering service) a temporary credential to open the outside door (or garage door)
let access to electricity (for electromobility sharing) outside of the house and authentify user, count electricity consumption and send him/her a bill. It's pretty like a Wifi beacon, that delivers a service for others. Like for DIY mode, it is not required to connect any manufacturing cloud. The lock or the energy counter should be autonomous.

I'm able to offer the cryptographic protocol for authentication and payement -> why not having new ESPhome components for that ?

Additional context

This will be a huge request in the future if any house is able to produce an income for its owner.

It seems that any ESP can manage the two modes simultaneously, I don't see the point not to have this feature with ESPHome. To get the Captive portal feature still active, it may be possible to have the (AP) HotSpot on one port and ActivePortal on another port

It seems hard (for me) to change directly the code and mix with auto-generated code. Is there a way to change (add) a C++ code into yaml ?

esphome / feature-requests

Enable to configure Wifi with both STA and AP modes for house external services #1100