Device Posture Collector
Collects a minimal device posture snapshot suitable for fleet ops.
Notes:
Intentionally avoids stable identifiers (IMEI/serial/SSAID).
Device Owner status is a key signal for kiosk reliability.
Includes key attestation status for security compliance reporting.
v0.3.0: Extended with battery, storage, connectivity, and device groups.
Privacy (GDPR Art. 5): No PII is collected. Only aggregate device state. Power Efficiency (BSI SYS.3.2.2.A8): Uses cached values, no wake locks.