feat: expand MAC OUI database with router, switch, AP, NAS, and camera vendors

Moves the OUI mapping from an inline dict in fingerprint.py into
data/oui_database.json grouped by vendor, matching the service_signatures
data-file pattern. Adds ~100 curated OUIs covering MikroTik, Ubiquiti,
Synology, QNAP, Cisco, Aruba, Juniper, Hikvision, Dahua, Reolink, Axis,
Raspberry Pi, Dell, Supermicro, and others. Existing IoT vendors and
hypervisor OUIs are preserved.

For multi-product vendors the OUI is tagged with the most common homelab
category (e.g. Ubiquiti -> ap) and port hints in suggest_node_type
continue to upgrade ambiguous matches (Ubiquiti + BGP -> router).

backend/tests/test_fingerprint.py

@@ -2,7 +2,12 @@ from unittest.mock import patch
 
 import pytest
 
-from app.services.fingerprint import fingerprint_ports, match_port, suggest_node_type
+from app.services.fingerprint import (
+    fingerprint_ports,
+    match_port,
+    suggest_node_type,
+    suggest_type_from_mac,
+)
 
 MOCK_SIGNATURES = [
     {"port": 80, "protocol": "tcp", "banner_regex": None, "service_name": "HTTP", "icon": "🌐", "category": "web", "suggested_node_type": "server"},
@@ -173,3 +178,74 @@ def test_suggest_node_type_iot_wins_over_server_when_mqtt_present():
         {"port": 1883, "protocol": "tcp"},
     ])
     assert result == "iot"
+
+
+# ── OUI vendor detection ──────────────────────────────────────────────────────
+
+def test_suggest_type_from_mac_mikrotik_returns_router():
+    # The motivating case: MikroTik MAC should be recognized as a router
+    assert suggest_type_from_mac("4c:5e:0c:11:22:33") == "router"
+    assert suggest_type_from_mac("b8:69:f4:aa:bb:cc") == "router"
+
+
+def test_suggest_type_from_mac_ubiquiti_returns_ap():
+    # Ubiquiti makes routers, switches, APs, cameras — most homelab gear is UniFi APs,
+    # so OUI defaults to "ap". Port hints can still upgrade to "router" if BGP/VPN open.
+    assert suggest_type_from_mac("24:a4:3c:11:22:33") == "ap"
+    assert suggest_type_from_mac("fc:ec:da:aa:bb:cc") == "ap"
+
+
+def test_suggest_type_from_mac_synology_returns_nas():
+    assert suggest_type_from_mac("00:11:32:11:22:33") == "nas"
+
+
+def test_suggest_type_from_mac_qnap_returns_nas():
+    assert suggest_type_from_mac("24:5e:be:aa:bb:cc") == "nas"
+
+
+def test_suggest_type_from_mac_hikvision_returns_camera():
+    assert suggest_type_from_mac("28:57:be:11:22:33") == "camera"
+
+
+def test_suggest_type_from_mac_dahua_returns_camera():
+    assert suggest_type_from_mac("3c:ef:8c:aa:bb:cc") == "camera"
+
+
+def test_suggest_type_from_mac_cisco_returns_switch():
+    assert suggest_type_from_mac("b8:38:61:11:22:33") == "switch"
+
+
+def test_suggest_type_from_mac_raspberry_pi_returns_server():
+    assert suggest_type_from_mac("b8:27:eb:11:22:33") == "server"
+
+
+def test_suggest_type_from_mac_handles_uppercase():
+    # MACs may arrive in any case; lookup must be case-insensitive
+    assert suggest_type_from_mac("4C:5E:0C:11:22:33") == "router"
+
+
+def test_suggest_type_from_mac_unknown_oui_returns_none():
+    assert suggest_type_from_mac("00:00:01:11:22:33") is None
+
+
+def test_suggest_node_type_mikrotik_mac_returns_router_no_ports():
+    # MikroTik device with no scanned ports should still be classified as router via MAC
+    assert suggest_node_type([], mac="4c:5e:0c:11:22:33") == "router"
+
+
+def test_suggest_node_type_synology_mac_with_http_returns_nas():
+    # NAS priority beats server, so a Synology MAC + open HTTP → nas
+    result = suggest_node_type(
+        [{"port": 80, "protocol": "tcp"}],
+        mac="00:11:32:11:22:33",
+    )
+    assert result == "nas"
+
+
+def test_suggest_node_type_ubiquiti_mac_with_bgp_upgrades_to_router():
+    # Ubiquiti OUI suggests "ap", but BGP port hint upgrades to "router" (higher priority)
+    result = suggest_node_type(
+        [{"port": 179, "protocol": "tcp"}],
+        mac="24:a4:3c:11:22:33",
+    )
+    assert result == "router"