Throttle Kalman trackable motion streams

[jillesvangurp]

Summary

• suppress native trackable motion publication when Kalman filtering is enabled so the stream is driven by the throttled derived path
• keep native location publication unchanged
• key Kalman state by trackable and CRS so alternating local/EPSG:4326 upstream updates do not reset publication throttle state

Root cause

trackable_motions included unthrottled native upstream events before locations reached the Kalman decision queue. In addition, alternating CRS inputs for the same trackable could reset Kalman state and bypass the intended emit interval.

Validation

• go test ./internal/hub -run 'TestKalman|TestProcessNativeLocation'
• go test $(go list ./... | grep -v '/tests/integration')