Restore Kalman trackable motion publication

[jillesvangurp]

Summary

• publish same-CRS Kalman-derived trackable motion events when the decision stage emits
• preserve the previous suppression of raw native trackable motion events while Kalman filtering is enabled
• add a regression test for the missing stream path

Root cause

The 0.1.7 fix suppressed raw native trackable_motions, but the derived path only emitted the transformed CRS variant. On live traffic this filtered out the movement stream entirely.

Validation

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