Get activity streams
Retrieves time-series stream data for a specific activity. Streams are the raw spatial and sensor data recorded during an activity, including GPS coordinates, speed, heart rate, power, etc. Each stream type returns an array of values that correspond to specific time points during the activity. All requested streams have the same number of data points, aligned by index. Common use cases: - GPS track visualization: request 'latlng', 'altitude', 'time' - Performance analysis: request 'heartrate', 'cadence', 'watts', 'time' - Pace/speed analysis: request 'velocity_smooth', 'distance', 'time' Requires activity:read scope. Requires activity:read_all scope for Only Me (private) activities.