Add Garmin/Fitbit OUIs; consolidate personal device detection into is_personal_device()

Garmin and Fitbit wearables use globally-assigned OUI MACs (no private addressing)
so the LAA bit check misses them. Added their OUIs to MOBILE_DEVICE_OUIS.

Consolidated all three detection signals into is_personal_device():
1. Explicit config (device_labels, personal_devices)
2. OUI table (phones + Garmin/Fitbit)
3. LAA bit (iOS 14+/Android 10+ private MACs)

Occupancy _is_personal now delegates to is_personal_device instead of duplicating logic.

net_alerter/net_alerter.py

@@ -116,6 +116,10 @@ MOBILE_DEVICE_OUIS = {
     "001555", "001620", "001645", "001693", "0016B8", "001730", "0017F6",
     "001822", "001888", "0018F8", "001913", "001985", "001A45", "001A92",
     "001AFC",
+    # Garmin (GPS watches/wearables with WiFi — do not use private MACs)
+    "086698", "F8B5AB", "E87941", "1430C6", "801F02", "68F3B1", "283B96", "24DEC6",
+    # Fitbit (wearables with WiFi sync — do not use private MACs)
+    "E890AC", "88A70E", "E407AA", "A41566", "008B17",
 }
 
 # Personal device tracking
@@ -728,26 +732,31 @@ def load_env():
 
 def is_personal_device(mac: str) -> bool:
     """
-    Check if MAC is a personal device (mobile OUI or manually configured).
+    Check if MAC belongs to a phone or wearable.
-    Returns True if device OUI is in MOBILE_DEVICE_OUIS OR mac is in personal_devices set.
+
+    Three signals, checked in order:
+    1. Explicit config — device_labels or personal_devices (operator-configured)
+    2. OUI table — MOBILE_DEVICE_OUIS covers phones + Garmin/Fitbit (no private MACs)
+    3. LAA bit — locally-administered bit set = iOS 14+/Android 10+ private MAC = phone/watch
     """
-    # Normalize MAC
     mac_normalized = _normalize_mac(mac)
-    if not mac_normalized:  # Skip invalid MACs
+    if not mac_normalized:
         return False
-    
+
     oui = mac_normalized[:6]
 
-    # Check personal_devices set first (manually configured)
     with personal_lock:
-        if mac_normalized in personal_devices:
+        if mac_normalized in personal_devices or mac_normalized in device_labels:
             return True
 
-    # Check against MOBILE_DEVICE_OUIS
     if oui in MOBILE_DEVICE_OUIS:
         return True
 
-    return False
+    # Locally-administered bit: modern phones randomize MACs; TVs/infra don't
+    try:
+        return bool(int(mac_normalized[:2], 16) & 0x02)
+    except ValueError:
+        return False
 
 
 def lookup_oui(mac: str) -> str:
@@ -901,18 +910,9 @@ def _update_occupancy_state_unlocked() -> None:
     """
     global location_occupancy
 
-    # Detect phones/wearables via LAA MAC (locally-administered bit set in first octet).
+    # Delegate to is_personal_device: checks explicit config, OUI table (phones + Garmin/Fitbit),
-    # iOS 14+, Android 10+ all use private/random MACs — this bit is always set.
+    # and LAA bit (iOS 14+/Android 10+ private MACs). No pre-config needed for modern phones.
-    # TVs, gateways, smart home devices use globally-assigned OUI MACs (bit clear).
+    _is_personal = is_personal_device
-    # Explicit device_labels / personal_devices also qualify (older phones, pre-config).
-    def _is_personal(mac: str) -> bool:
-        n = _normalize_mac(mac)
-        if n in device_labels or n in personal_devices:
-            return True
-        try:
-            return bool(int(n[:2], 16) & 0x02)  # locally-administered bit
-        except ValueError:
-            return False
 
     active_enrolled_count = 0
     for mac, dev in known_devices.items():