b4db41a400
All three hardware drivers (Olimex, generic_esp32, generic_esp8266) now
probe with the first request and bail immediately on failure.
Before: offline board with 4 relays + 3 inputs = 7 requests × 3 s timeout
= up to 21 s of blocking + 7 log lines per recheck cycle.
After: exactly 1 request × 3 s timeout regardless of I/O count.