Merge feature/settings-icons (b9c12cb..22aad4b). docs/RUNNING.md and
tools/cycle_lib/installed_fresh.py merge without conflict: the
settings-icons trust set (ADDITIONS/TRUST_PAYLOAD, mirror-slab kept as
ADDITIONS_MIRRORSLAB for rollback) sits beside the brightness and
fn-keys options.
gpu/adreno-kext/kext: SnapAdreno next f54b9ec, the merge of all three
SnapAdreno feature branches; gpu/adreno-kext/plugin: SnapMetal 936d51b
(feature/settings-icons).