1. Fuzz Tests: add esp_timer_create_args_t, esp_timer_create(),
esp_timer_start_periodic(), esp_timer_delete() stubs to
esp_stubs.h — csi_collector.c uses these for channel hop timer.
2. QEMU Build: add libgcrypt20-dev to apt dependencies —
Espressif QEMU's esp32_flash_enc.c includes <gcrypt.h>.
Bump cache key v4→v5 to force rebuild with new dep.
3. NVS Matrix: switch to subprocess-first invocation of
nvs_partition_gen to avoid 'str' has no attribute 'size' error
from esp_idf_nvs_partition_gen API change. Falls back to
direct import with both int and hex size args.
Co-Authored-By: claude-flow <ruv@ruv.net>
a333951349