f913167973
sys_write passes u64::MAX as the offset sentinel for non-positioned file descriptors. The proc scheme's require_zero_offset rejected this value, causing bootstrap's tcb_activate to crash with EINVAL when writing EnvRegisters (fsbase) back to the regs/env handle. This was the root cause of the 'Invalid opcode fault' during bootstrap (PID 0) that prevented redbear-mini from reaching a login prompt.