199d0da675
New seen_macs table: permanent, insert-only, MAC-keyed record of the first time each device was ever seen -- deliberately decoupled from devices.first_seen (IP-keyed, would false-positive on every DHCP lease change). Bootstrap-safe: first call seeds the baseline from whatever's currently on the network without alerting on all 71+ existing devices at once. Verified locally: bootstrap call reports nothing new, repeat calls with the same MACs report nothing new, one genuinely new MAC gets reported exactly once. Pushes a Home Assistant persistent_notification when a new MAC appears (gated behind HOME_ASSISTANT_TOKEN + homeAssistant.url in hosts.yaml -- missing config just means no push, detection still runs). Also surfaced directly in the dashboard as a blue "new" badge for anything first seen in the last 24h, independent of HA config. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>