0.18.0

sidereon 0.18.0: this interface gains the GNSS/INS fusion stack (mechanization configuration, EKF
and UKF filtering, loose and tight measurements, robust loose update options, the RTS smoother,
time synchronization, and the serializable filter state), the deterministic scenario simulator
(bit-reproducible synthetic observables plus the ground-truth term ledger), and closed-form signal
analysis (spectra, spectral separation coefficients, DLL jitter, multipath envelopes), each with
parity tests against core values.
Full details: https://github.com/neilberkman/sidereon/releases/tag/v0.18.0