Add raw SPC convective outlook source

internal/sources/builtins_test.go

@@ -87,6 +87,7 @@ func TestRegisterBuiltinsRegistersAllCurrentDrivers(t *testing.T) {
 		"openmeteo_observation",
 		"openmeteo_forecast",
 		"openweather_observation",
+		"spc_convective_outlook",
 	}
 
 	for _, driver := range drivers {
@@ -105,13 +106,18 @@ func sourceConfigForDriver(driver string) config.SourceConfig {
 	if driver == "openweather_observation" {
 		url = "https://example.invalid?units=metric"
 	}
+	params := map[string]any{
+		"url":        url,
+		"user_agent": "test-agent",
+	}
+	if driver == "spc_convective_outlook" {
+		params["latitude"] = 38.6239
+		params["longitude"] = -90.3571
+	}
 	return config.SourceConfig{
 		Name:   "test-source",
 		Driver: driver,
 		Mode:   config.SourceModePoll,
-		Params: map[string]any{
-			"url":        url,
-			"user_agent": "test-agent",
-		},
+		Params: params,
 	}
 }