Heartbeat POST now captures the response body (up to 2048 bytes) and
looks for a "config" object. If cfg_version advances past the stored
value and all tunable fields pass range validation, the new tuning is
applied to g_cv and persisted to NVS.
- cv_tuning_validate: pure range checker (cv.cpp)
- cv_apply_tuning / cv_get_tuning: mutex-guarded helpers in main.cpp
exposed via cv_apply.h; 500 ms timeout, drop on contention
- post_json now returns int (HTTP status) and optionally captures the
response body; existing callers check == 200
- heartbeat: parse → cfg_version check → override present fields →
validate → apply → save. Silent no-op when server returns no config.
- 3 new native tests (15/15 pass). timercam flash 1,423,897 bytes
(+9,828 vs baseline).
Peter Woolery
21f3bc77d1