Add v0.12.0: equatorial GiST operator class + DE moon equatorial functions
Feature A: GiST index for equatorial type with KNN ordering (<-> strategy 15).
24-byte float-precision spherical bounding box, RA-wrapping aware merge/split,
Vincenty lower-bound distance for correct KNN pruning. Apollo-hardened with
epsilon-widened bounds, circular-aware picksplit, compile-time size assertions.
Feature B: 4 new DE moon equatorial functions (galilean_equatorial_de,
saturn_moon_equatorial_de, uranus_moon_equatorial_de, mars_moon_equatorial_de).
Same-provider rule enforced, transparent VSOP87 fallback.
120 -> 132 SQL objects. 22 regression suites passing.
Ryan Malloy
84ce1f1b8d