Calibrated confidence on every Context Engine signal

Klyo Context Engine v0.6.3 ships a calibrated confidence value alongside every signal. The calibration is fit on the combined validation corpora and is conservative by construction: it cannot change a classification, only the confidence number attached to it. Audit logs and downstream policy thresholds now read a number that more reliably matches the underlying probability the signal is correct.

The model version stamp in the audit trail is bumped to klyo-ctx-0.6.0 so consumers can distinguish calibrated from un-calibrated signals when comparing historic records.

Recall on real personal data stays at 100% after calibration, verified end to end.

No action required.