- Replace split zero_force_segment / zero_sensor_segment with unified
zero_obs_async() — a single memset covers all three obs segments
(force, torque, sensor), resetting the step accumulator.
- Add _obs_accum_steps counter so read_*(normalize=True) returns the
physically meaningful per-step average for all telemetry fields.
- Sensor now always applies area-normalisation internally; the normalize
parameter only controls the additional time-normalisation step.
- run() gains zero_obs=True parameter (default) to control reset-on-step.
- 7 new integration tests covering accumulation, zeroing, and normalise.
- Fix bug in test_sensor_accuracy.py (undefined loop variable i).
- Bump version to 0.4.0 for the API change.
Co-authored-by: Cursor <cursoragent@cursor.com>
