Delay/Timed/Manual initialisation of sensor component code

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

I have a battery powered ESP32 and a Hydreon RG-9 rainsensor.

What I am trying to do is this:

- ESP wakes from a period of deep sleep.
- ESP requests the state of a rooflight in Home Assistant
- If the rooflight is closed, then the ESP goes back to sleep
- If the rooflight is open, then I power up the RG-9 and start sending readings back to HA to automate closing of the rooflight when it rains.
- Once closed, the ESP goes back to the sleep routine

Most of this works, but the RG-9 sensor component is loaded when the ESP wakes up/boots and as the physical RG-9 device is not yet powered, then the component initialization fails and I can't see any way to re-initialize it when I need to. I have tried using component.update() but this doesn't appear to help. Ideally need some kind of "component.init: id" function that I can call after I have powered up the RG-9. Maybe with a "component:initDelay INT" option so a user can decide either to delay initialization for "n" seconds or set it to 0 so it is never automatically initialized and has to be triggered by code later.

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

The issue is that the component sensor code is being initialized before the physical device is powered on. Ideally I would like to be able to control when the sensor code is loaded so I can run it *after* the ESP has validated the use case and enabled a GPIO to turn on the rain sensor (via a small mosfet but that isn't important).

I have achieved all I want using arduino C code and HA MQTT but I really like the deep integration with HA offered by ESPHome and the ability to easily do OTA updates etc.

**Additional context**

I have asked about this on discord and was told that it isn't something that is available right now. There is my example yaml code in this thread too:

https://discord.com/channels/429907082951524364/1157611493643268147

Thanks

Start by reviewing the example YAML referenced in the Discord thread and the reported behavior of component.update(). The intended result is a way to delay or manually trigger sensor initialization after the ESP32 powers the RG-9 through GPIO, while preserving the existing deep-sleep workflow.

Written by the indexing model from the issue text.