feat: enhance System Health dashboard with rich telemetry and visualizations

Add SVG arc gauge, per-core CPU bars, temperature sparkline, network
interface monitoring with bandwidth deltas, disk I/O rates, 3D globe
with observer location, weather overlay, battery/fan/throttle support,
and process grid layout. New /system/location and /system/weather endpoints.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tests/test_system.py

@@ -30,6 +30,32 @@ def test_metrics_returns_expected_keys(client):
     assert 'uptime_human' in data['system']
 
 
+def test_metrics_enhanced_keys(client):
+    """GET /system/metrics returns enhanced metric keys."""
+    _login(client)
+    resp = client.get('/system/metrics')
+    assert resp.status_code == 200
+    data = resp.get_json()
+    # New enhanced keys
+    assert 'network' in data
+    assert 'disk_io' in data
+    assert 'boot_time' in data
+    assert 'battery' in data
+    assert 'fans' in data
+    assert 'power' in data
+
+    # CPU should have per_core and freq
+    if data['cpu'] is not None:
+        assert 'per_core' in data['cpu']
+        assert 'freq' in data['cpu']
+
+    # Network should have interfaces and connections
+    if data['network'] is not None:
+        assert 'interfaces' in data['network']
+        assert 'connections' in data['network']
+        assert 'io' in data['network']
+
+
 def test_metrics_without_psutil(client):
     """Metrics degrade gracefully when psutil is unavailable."""
     _login(client)
@@ -45,6 +71,11 @@ def test_metrics_without_psutil(client):
         assert data['cpu'] is None
         assert data['memory'] is None
         assert data['disk'] is None
+        assert data['network'] is None
+        assert data['disk_io'] is None
+        assert data['battery'] is None
+        assert data['boot_time'] is None
+        assert data['power'] is None
     finally:
         mod._HAS_PSUTIL = orig
 
@@ -87,3 +118,75 @@ def test_stream_returns_sse_content_type(client):
     resp = client.get('/system/stream')
     assert resp.status_code == 200
     assert 'text/event-stream' in resp.content_type
+
+
+def test_location_returns_shape(client):
+    """GET /system/location returns lat/lon/source shape."""
+    _login(client)
+    with patch('routes.system.contextlib.suppress'):
+        resp = client.get('/system/location')
+    assert resp.status_code == 200
+    data = resp.get_json()
+    assert 'lat' in data
+    assert 'lon' in data
+    assert 'source' in data
+
+
+def test_location_falls_back_to_config(client):
+    """Location endpoint returns config defaults when GPS unavailable."""
+    _login(client)
+    with patch('routes.system.DEFAULT_LATITUDE', 40.7128, create=True), \
+         patch('routes.system.DEFAULT_LONGITUDE', -74.006, create=True):
+        # Mock the import inside _get_observer_location
+        resp = client.get('/system/location')
+    assert resp.status_code == 200
+    data = resp.get_json()
+    assert 'source' in data
+
+
+def test_weather_requires_location(client):
+    """Weather endpoint returns error when no location available."""
+    _login(client)
+    # Without lat/lon params and no GPS state or config
+    resp = client.get('/system/weather')
+    assert resp.status_code == 200
+    data = resp.get_json()
+    # Either returns weather or error (depending on config)
+    assert 'error' in data or 'temp_c' in data
+
+
+def test_weather_with_mocked_response(client):
+    """Weather endpoint returns parsed weather data with mocked HTTP."""
+    _login(client)
+    mock_resp = MagicMock()
+    mock_resp.status_code = 200
+    mock_resp.json.return_value = {
+        'current_condition': [{
+            'temp_C': '22',
+            'temp_F': '72',
+            'weatherDesc': [{'value': 'Clear'}],
+            'humidity': '45',
+            'windspeedMiles': '8',
+            'winddir16Point': 'NW',
+            'FeelsLikeC': '20',
+            'visibility': '10',
+            'pressure': '1013',
+        }]
+    }
+    mock_resp.raise_for_status = MagicMock()
+
+    import routes.system as mod
+    # Clear cache
+    mod._weather_cache.clear()
+    mod._weather_cache_time = 0.0
+
+    with patch('routes.system._requests') as mock_requests:
+        mock_requests.get.return_value = mock_resp
+        resp = client.get('/system/weather?lat=40.7&lon=-74.0')
+
+    assert resp.status_code == 200
+    data = resp.get_json()
+    assert data['temp_c'] == '22'
+    assert data['condition'] == 'Clear'
+    assert data['humidity'] == '45'
+    assert data['wind_mph'] == '8'