feat(Q3): Open-Meteo weather fetcher with hourly caching

tests/unit/test_weather.py

@@ -0,0 +1,39 @@
+import time
+from unittest.mock import patch, MagicMock
+from vigilar.detection.weather import WeatherFetcher, _weather_code_to_text
+
+
+def test_get_conditions_returns_dict_on_success():
+    fetcher = WeatherFetcher()
+    mock_response = MagicMock()
+    mock_response.status_code = 200
+    mock_response.json.return_value = {"current": {"temperature_2m": 15.5, "weather_code": 2}}
+    with patch("vigilar.detection.weather.requests.get", return_value=mock_response):
+        result = fetcher.get_conditions(45.0, -85.0)
+    assert result is not None
+    assert result["temperature_c"] == 15.5
+    assert isinstance(result["conditions"], str)
+
+
+def test_get_conditions_returns_none_on_failure():
+    fetcher = WeatherFetcher()
+    with patch("vigilar.detection.weather.requests.get", side_effect=Exception("offline")):
+        result = fetcher.get_conditions(45.0, -85.0)
+    assert result is None
+
+
+def test_get_conditions_caches():
+    fetcher = WeatherFetcher()
+    mock_response = MagicMock()
+    mock_response.status_code = 200
+    mock_response.json.return_value = {"current": {"temperature_2m": 10.0, "weather_code": 0}}
+    with patch("vigilar.detection.weather.requests.get", return_value=mock_response) as mock_get:
+        fetcher.get_conditions(45.0, -85.0)
+        fetcher.get_conditions(45.0, -85.0)
+        assert mock_get.call_count == 1
+
+
+def test_weather_code_mapping():
+    assert _weather_code_to_text(0) == "Clear sky"
+    assert _weather_code_to_text(61) == "Light rain"
+    assert _weather_code_to_text(999) == "Unknown"