Photon (managed iMessage) shipped without a _PLATFORM_DEFAULTS entry, so it
inherited the noisy global ('all') display defaults and narrated tool
progress / heartbeats / busy-ack detail into a permanent-message iMessage
thread. Register it as TIER_LOW alongside BlueBubbles and Signal, plus a
regression test guarding the tier.
Salvaged from #50511 (Photon tier piece only).
