A player stands down from self-updating when another device owner manages the panel,
on the assumption that the MDM distributes packages instead. That assumption does not
always hold: an operator may run an MDM for policy alone and still want ScreenTinker's
OTA to own the player. Until now there was no way to say so — the stand-down was a
client-side decision with no operator input.
OTA_ALLOW_MANAGED_DEVICES=1 makes the server advertise `allow_managed: true` in
/api/update/check, and players skip the stand-down. Default off: the safe behaviour
stays the default, and only an explicit opt-in changes it.
Absence is not consent. The client parses the field with a false default, so a newer
player against an older server that has never heard of it still stands down; and the
server always emits the key, so a player can tell "the operator said no" from "this
server has no opinion". Config parsing is strict for the same reason — only 1/true
enable it, and anything else, including a plausible typo like "ture" or "yes", lands
on the safe side rather than riding JavaScript truthiness.
This deliberately does NOT grant silent install. Off device-owner, and without
DELEGATION_PACKAGE_INSTALLATION delegated by the MDM, Android still raises a confirm
dialog somebody has to accept, so the override alone will not fix a fleet whose
installs are failing at that dialog — delegating the scope is the real fix there. The
README says so at the point of use, because reaching for this flag is the natural
mistake.
Only reachable because the stand-down now runs after the version check rather than
before it; it needs the server's answer in hand to consult.
