POST /api/provision was a second pairing endpoint that paired a device by code but,
unlike POST /api/provision/pair, did NOT assign a workspace, enforce checkDeviceLimit, or
emit device:paired / dashboard:device-added - a silently-diverging duplicate that no
client ever called. It now returns 410 Gone and points callers at /pair, so
/api/provision/pair is the single, fully-protected pairing endpoint. The mount stays in
the JWT-only partition, so a Bearer st_ token still gets 401 (requireAuth) before the 410.
Closes#90
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>