I feel like there was an app from the ACLU or EFF that did exactly that. Locked the device and started recording on panic button combo, and if I am remembering correctly had the ability to auto-upload to a cloud in case of device seizure.

EDIT: Ah, ok I was confused. It was the ACLU Mobile Justice app which was cloud based, but it was shutdown just last month. They point to external entities having access to their database as the reason.

Any reason you avoided the official Raspberry Pi Imager software? You really can just configure a headless OS all before flashing the SD card. Choose RPi OS lite from the list, then set up your hostname, username, password, wireless and turn on SSH service. Then all you have to do after flashing is plug in power and SSH in. None of this display troubleshooting would be needed.

Two questions:

Do you have anything between the Pi and Display, like an HDMI switch? Sometimes the Pi incorrectly sets the display resolution if it can’t communicate with the display directly.

Did you use the Raspberry Pi Imager program? You can configure SSH and WiFi, before you even image to SD. It’s how I set up my headless stuff so I don’t have to futz with connecting displays.