[v1.0.0]

The C ABI uses celestial_ exports, Celestial records and one CELESTIAL_TARGET_* code family. Existing 0.x binaries and source callers must migrate; no compatibility forwarders are provided.
Independent ecliptic/equatorial positions and civil houses are available from C++ and C, with immutable Python result values. Positions retain caller order and provider windows without computing rates or houses.
Model keys distinguish Delta T, nutation and position sources. Selected-model results record their resolved identities; capability queries describe TT target domains and the separate civil-house policy.
Native error kinds distinguish invalid input from computation, resource and internal failures, including when no error message could be allocated. Automatic logging and logging configuration APIs are removed.
Sized strings count the terminating NUL. JavaScript Sun distance is named distanceAu; JavaScript gains no public position, equatorial, house, event or capability query API.

calendar::Datetime accepts raw durations and checks original date/time values before narrowing.
Jieqi table schema celestial-calendar/jieqi-table@2 stores model UT1 as jd_ut1 / iso_ut1, with verified build provenance, instead of presenting it as UTC.
Charts and civil houses share civil-year and UTC admission. Algo4 requires derived TT before 2035-01-01, excluding roughly the last 71.5 UT1 seconds of 2034. Houses do not inherit the chart's target/rate window.

See Migrating to 1.0 for replacement names, ownership protocols and changed failure behavior. The changelog retains the full development history.