- Both olimex_esp32_c6_evb and olimex_esp32_c6_evb_pn532 drivers now
sign every API request with X-Request-Time / X-Request-Sig headers
using HMAC-SHA256(api_secret, METHOD:path:unix_timestamp)
- Board model gains api_secret column (nullable, default None)
- boards.py edit route saves api_secret from form
- edit.html adds API Secret input with cryptographic Generate button
- If api_secret is empty/None, headers are omitted (backward compat)
The previous _compute_sign_key() function indexed into a base64 string
derived from the full SonoffLAN REGIONS dict (~243 entries). Our partial
dict only produced a 7876-char a string but needed index 7872+, so the
function must use the full dict.
Solution: pre-compute the key once from the full dict and hardcode the
resulting 32-byte ASCII key. This is deterministic — the SonoffLAN
algorithm always produces the same output regardless of when it runs.
The sonoff_ewelink driver now loads cleanly alongside all other drivers.
