Add presence DB schema; fix BLE passive scan mode (bleak #1440)

net_alerter/presence_schema.sql

@@ -0,0 +1,38 @@
+-- Presence intelligence schema — Phase 1 (WiFi-only)
+-- Load with: sqlite3 presence.db < presence_schema.sql
+
+PRAGMA journal_mode=WAL;
+
+CREATE TABLE IF NOT EXISTS persons (
+    mac TEXT PRIMARY KEY,
+    hostname TEXT,
+    vendor TEXT,
+    first_seen REAL NOT NULL,
+    last_seen REAL NOT NULL,
+    state TEXT NOT NULL DEFAULT 'ABSENT',
+    certainty REAL NOT NULL DEFAULT 0.0,
+    session_count INTEGER NOT NULL DEFAULT 1,
+    total_minutes REAL NOT NULL DEFAULT 0.0
+);
+
+CREATE TABLE IF NOT EXISTS signals (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    mac TEXT NOT NULL,
+    signal_type TEXT NOT NULL,  -- mdns | arp
+    certainty REAL NOT NULL,
+    observed_at REAL NOT NULL
+);
+
+CREATE TABLE IF NOT EXISTS events (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    mac TEXT NOT NULL,
+    hostname TEXT,
+    event_type TEXT NOT NULL,  -- arrived | departed | updated
+    certainty REAL NOT NULL,
+    timestamp REAL NOT NULL
+);
+
+CREATE INDEX IF NOT EXISTS idx_signals_mac ON signals(mac);
+CREATE INDEX IF NOT EXISTS idx_signals_mac_time ON signals(mac, observed_at);
+CREATE INDEX IF NOT EXISTS idx_events_mac ON events(mac);
+CREATE INDEX IF NOT EXISTS idx_events_timestamp ON events(timestamp);