Wrap BleakScanner context manager in try-except to detect adapter
initialization errors. If 'No Bluetooth adapters found' or similar, log
warning and set shutdown event to trigger graceful exit with code 0.
Prevents systemd restart loop on hardware without BT adapter (e.g. OPi).
- Reject dash/colon MAC-format device names (e.g. 45-48-39-7F-73-C7)
from open mode — were slipping past is_generic_name()
- Add exponential backoff (1s, 2s) on Matrix 429/5xx, max 3 attempts —
startup burst was rate-limiting and dropping alerts
- Commit active scanner flag (scanning_mode=active) that was in working
tree but not in prior commit c0b91e9 despite the commit message
- Add 3 tests: MAC format filter, 429 retry success, 429 give-up
Fixes DevTrack #518
Passive mode fails on Debian bookworm bleak 0.20.2 without or_patterns filter.
Active mode is functionally equivalent for building-level presence detection
and actually yields more complete advertisement data including device names.
Cobra