The app knew about bonded devices only in passing - syncPairedDevices marked
them tracked and threw the bond state away - so nothing downstream could tell
a paired device from one merely seen. Adds devices.paired (schema 17), set
from ACTION_BOND_STATE_CHANGED and from the bonded list at startup, and sends
it as a `paired` column on every uploaded row.
The flag is its own column rather than inferred from is_tracked, which answers
a different question: a device can be tracked without ever having been paired.
syncPairedDevices clears the flag before re-asserting it from getBondedDevices.
A device unpaired while the service was dead never broadcast BOND_NONE, so the
bonded list is the only reliable answer at startup, and without the clear such
a device would stay marked paired forever.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>