feat: v0.1.4 — device intelligence dashboard

Add tabbed dashboard at /dashboard/ with three D3.js visualizations:
- Vendor treemap (devices grouped by type and vendor)
- SSID social graph (force-directed, shared probed SSIDs as edges)
- Fingerprint clusters (packed circles by device behavior)

Intelligence API endpoints at /api/v1/intelligence/ with param
validation. Dashboard built on htmx + Pico CSS dark theme + D3 v7,
all vendored locally (make vendor). 13 new tests (59 total).

tests/test_api/test_intelligence.py

@@ -0,0 +1,136 @@
+"""Intelligence API tests."""
+from datetime import datetime, UTC, timedelta
+from esp32_web.extensions import db
+from esp32_web.models import Device, Probe, Sighting, Sensor
+
+
+def _seed_devices(app):
+    """Create test devices, probes, and sightings."""
+    with app.app_context():
+        sensor = Sensor(hostname='test-sensor', ip='192.168.1.1')
+        db.session.add(sensor)
+        db.session.flush()
+
+        d1 = Device(mac='aa:bb:cc:dd:ee:01', device_type='wifi',
+                     vendor='Apple, Inc.', first_seen=datetime.now(UTC),
+                     last_seen=datetime.now(UTC))
+        d2 = Device(mac='aa:bb:cc:dd:ee:02', device_type='wifi',
+                     vendor='Samsung', first_seen=datetime.now(UTC),
+                     last_seen=datetime.now(UTC))
+        d3 = Device(mac='aa:bb:cc:dd:ee:03', device_type='ble',
+                     company_id=0x004C, first_seen=datetime.now(UTC),
+                     last_seen=datetime.now(UTC))
+        db.session.add_all([d1, d2, d3])
+        db.session.flush()
+
+        now = datetime.now(UTC)
+        # Both d1 and d2 probe "HomeNet"
+        db.session.add_all([
+            Probe(device_id=d1.id, sensor_id=sensor.id, ssid='HomeNet',
+                  rssi=-50, channel=6, timestamp=now),
+            Probe(device_id=d2.id, sensor_id=sensor.id, ssid='HomeNet',
+                  rssi=-60, channel=6, timestamp=now),
+            Probe(device_id=d1.id, sensor_id=sensor.id, ssid='Office',
+                  rssi=-55, channel=1, timestamp=now),
+        ])
+        # Sightings
+        db.session.add_all([
+            Sighting(device_id=d1.id, sensor_id=sensor.id, rssi=-50, timestamp=now),
+            Sighting(device_id=d3.id, sensor_id=sensor.id, rssi=-70, timestamp=now),
+        ])
+        db.session.commit()
+
+
+# -- Vendor Treemap --
+
+def test_vendor_treemap_empty(client):
+    """Test treemap with no devices."""
+    response = client.get('/api/v1/intelligence/vendor-treemap')
+    assert response.status_code == 200
+    assert response.json['name'] == 'devices'
+    assert response.json['children'] == []
+
+
+def test_vendor_treemap_with_data(client, app):
+    """Test treemap returns grouped vendor data."""
+    _seed_devices(app)
+    response = client.get('/api/v1/intelligence/vendor-treemap')
+    assert response.status_code == 200
+    data = response.json
+    assert data['name'] == 'devices'
+    assert len(data['children']) > 0
+
+    # Find wifi group
+    wifi = next((c for c in data['children'] if c['name'] == 'wifi'), None)
+    assert wifi is not None
+    assert len(wifi['children']) >= 1
+
+    # Find ble group
+    ble = next((c for c in data['children'] if c['name'] == 'ble'), None)
+    assert ble is not None
+    assert len(ble['children']) >= 1
+
+
+# -- SSID Graph --
+
+def test_ssid_graph_empty(client):
+    """Test graph with no probes."""
+    response = client.get('/api/v1/intelligence/ssid-graph')
+    assert response.status_code == 200
+    assert response.json['nodes'] == []
+    assert response.json['links'] == []
+
+
+def test_ssid_graph_with_data(client, app):
+    """Test graph returns nodes and links for shared SSIDs."""
+    _seed_devices(app)
+    response = client.get('/api/v1/intelligence/ssid-graph?hours=24')
+    assert response.status_code == 200
+    data = response.json
+    assert len(data['nodes']) >= 2
+    # d1 and d2 share "HomeNet" → at least one link
+    assert len(data['links']) >= 1
+    link = data['links'][0]
+    assert 'HomeNet' in link['shared_ssids']
+    assert link['weight'] >= 1
+
+    # SSID summary present
+    assert len(data['ssids']) >= 1
+
+
+def test_ssid_graph_params(client, app):
+    """Test graph with custom parameters."""
+    _seed_devices(app)
+    response = client.get('/api/v1/intelligence/ssid-graph?hours=1&min_shared=5&limit=10')
+    assert response.status_code == 200
+    # With min_shared=5, no pairs should match
+    assert response.json['links'] == []
+
+
+# -- Fingerprint Clusters --
+
+def test_fingerprint_clusters_empty(client):
+    """Test clusters with no activity."""
+    response = client.get('/api/v1/intelligence/fingerprint-clusters')
+    assert response.status_code == 200
+    assert response.json['clusters'] == []
+    assert response.json['total_devices'] == 0
+
+
+def test_fingerprint_clusters_with_data(client, app):
+    """Test clusters group devices by behavior."""
+    _seed_devices(app)
+    response = client.get('/api/v1/intelligence/fingerprint-clusters?hours=24')
+    assert response.status_code == 200
+    data = response.json
+    assert data['total_devices'] >= 2
+    assert data['total_clusters'] >= 1
+
+    # Each cluster has expected structure
+    cluster = data['clusters'][0]
+    assert 'label' in cluster
+    assert 'device_count' in cluster
+    assert 'devices' in cluster
+    assert 'centroid' in cluster
+    assert 'probe_rate' in cluster['centroid']
+    assert 'sighting_rate' in cluster['centroid']