An existing product called PG Orbit (a mobile PostgreSQL client)
creates a naming conflict. pg_orrery — a database orrery built from
Keplerian parameters and SQL instead of brass gears.
Build system: control file, Makefile, Dockerfile, docker init script.
C source: GUC prefix, PG_FUNCTION_INFO_V1 symbol, header guards,
ereport prefixes, comments across ~30 files including vendored SGP4.
SQL: all 5 install/migration scripts, function name pg_orrery_ephemeris_info.
Tests: 9 SQL suites, 8 expected outputs, standalone DE reader test.
Documentation: CLAUDE.md, README.md, DESIGN.md, Starlight site infra,
36 MDX pages, OG renderer, logo SVG, docker-compose, agent threads.
All 13 regression suites pass. Docs site builds (37 pages).
Standalone test (test/test_de_reader.c): generates a synthetic 12KB
DE binary with known Chebyshev coefficients, exercises header parsing,
polynomial evaluation at 5 domain points, Earth derivation via
center=99, Moon geocentric, layout validation, range/body error paths,
NAN sentinel, and garbage file rejection. 55 tests, no PG dependency.
Makefile: add `make test-de-reader` target; also includes the earlier
sat_code C++ -> pure C sgp4 migration that was missed from prior commits.
astro_math.h: document that ecliptic_to_equatorial/equatorial_to_ecliptic
are NOT safe for aliased (in-place) calls — equ[1] is written before
equ[2] reads ecl[1]. The vendored sgp4/sdp4.c has separate in-place
versions using a temp variable.
