Two issues cause python3-validity to crash on startup, particularly
after reboot or when the sensor flash is uninitialized:

1. get_flash_info() in flash.py calls assert_status() on the response
   from command 0x3e, which throws on any 0x04xx status. These statuses
   indicate uninitialized flash, which is a normal condition that
   init_flash() is designed to handle. The crash prevents init_flash()
   from ever reaching its formatting logic.

   Fix: return an empty FlashInfo when status byte is 0x04, allowing
   init_flash() to proceed with flash formatting as intended.

2. send_init() in usb.py calls assert_status() on the init_hardcoded
   command, which fails with 0x0411 when no firmware is loaded. The
   very next lines check the 4302 (get_fw_info) response and fall
   through to init_hardcoded_clean_slate for exactly this case, but
   the assert prevents that path from ever being reached.

   Fix: remove assert_status() on init_hardcoded, allowing the
   existing clean slate fallback logic to work as designed.

Tested on Lenovo ThinkPad X1 Carbon Gen 5 with Validity VFS495
(138a:0097) sensor running Ubuntu 25.10 / kernel 6.17.