DEVICE_MARKER_RE expected "; === Device: NAME [AA:marker] (category) ===",
but device_config's own template (further down this file) generates
"; === Device: NAME (category) [AA:marker] ===" -- category parens before
the AA tag, not after. The regex never matched a real device comment, so
list_extensions() silently returned [] for every device on every install,
and /api/pstn-permissions served {"extensions": []} regardless of what was
actually in pstn-permissions.conf. That's why the Extensions tab's
Messaging/Voicemail checkboxes always rendered unchecked after a save +
reload even though the file itself had messaging=yes/voicemail=yes written
correctly -- the JS falls back to an all-default row when the endpoint
returns nothing. ea_list_devices() and the rename-device code parse the
same comment via string-splitting/a differently-shaped regex and were
already correct; this was the one broken parser.