- `bootloader_flash_execute_command_common`: whitelist the flash command
opcodes the REE actually uses; reject the rest
- `spi_flash_hal_* services`: a forged `host->driver` could hijack TEE
control flow since the HAL dispatches through it, so swap
`host->driver` to a TEE-rodata vtable around each HAL call
- Deny partition table and bootloader writes by default and permit
bootloader writes only when explicitly enabled via
`CONFIG_SPI_FLASH_DANGEROUS_WRITE_ALLOWED` option
- Protect the TEE-assigned interrupt pin configuration against REE
- Validate nested DS context pointers in start/finish_sign and bound
the result copy to the SoC max signature size
- Fix the stack usage in service dispatcher argument parsing
