ZMK Corne boot loop after flashing new firmware: check stale BLE bonds

When a ZMK Corne (Corne Min) keyboard boot-loops after flashing new firmware, suspect stale settings/BLE bonds left in flash from the previous firmware rather than a build/flash failure — CI only validates that the firmware builds, not runtime behavior against existing bonded state on the device. Trap: assuming the new firmware image itself is broken and re-flashing repeatedly looks like the fix, but the loop can persist because old bond/settings data in flash is incompatible with the new build. Fix: clear settings/BLE bonds (e.g. via bootloader double-tap + settings reset, or clearing the settings partition) before/after flashing when boot loops appear post-flash. Unconfirmed hypothesis as of Jul 11 2026 — verify against actual resolution once confirmed.