Update docs and CLAUDE.md for v0.12.0

CLAUDE.md: bump version to 0.12.0, function count to 132, test count
to 22, add v0.10-0.12 SQL files to layout, add gist_equatorial.c,
update function domains table, add DE moon equatorial to DE variants.

Docs: add equatorial GiST operator class section to operators-gist.mdx
(KNN queries, cone search, RA wrapping, polar behavior). Add 4 DE moon
equatorial functions to functions-de.mdx (galilean, saturn, uranus, mars).

CLAUDE.md

@@ -1,9 +1,9 @@
 # pg_orrery — A Database Orrery for PostgreSQL
 
 ## What This Is
-A database orrery — celestial mechanics types and functions for PostgreSQL. Native C extension using PGXS, 114 SQL functions, 9 custom types, covering satellites (SGP4/SDP4), planets (VSOP87 + optional JPL DE441), Moon (ELP2000-82B), 19 planetary moons (L1.2/TASS17/GUST86/MarsSat), stars (with proper motion and annual parallax), comets, asteroids (MPC catalog), Jupiter radio bursts, interplanetary Lambert transfers, equatorial RA/Dec coordinates with angular separation, atmospheric refraction, annual stellar aberration, and light-time correction.
+A database orrery — celestial mechanics types and functions for PostgreSQL. Native C extension using PGXS, 132 SQL objects (124 user-visible functions + 8 GiST support), 9 custom types, covering satellites (SGP4/SDP4), planets (VSOP87 + optional JPL DE441), Moon (ELP2000-82B), 19 planetary moons (L1.2/TASS17/GUST86/MarsSat), stars (with proper motion and annual parallax), comets, asteroids (MPC catalog), Jupiter radio bursts, interplanetary Lambert transfers, equatorial RA/Dec coordinates with GiST-indexed angular separation, atmospheric refraction, annual stellar aberration, and light-time correction.
 
-**Current version:** 0.10.0
+**Current version:** 0.12.0
 **Repository:** https://git.supported.systems/warehack.ing/pg_orrery
 **Documentation:** https://pg-orrery.warehack.ing
 
@@ -11,7 +11,7 @@ A database orrery — celestial mechanics types and functions for PostgreSQL. Na
 ```bash
 make PG_CONFIG=/usr/bin/pg_config           # Compile with PGXS
 sudo make install PG_CONFIG=/usr/bin/pg_config  # Install extension
-make installcheck PG_CONFIG=/usr/bin/pg_config  # Run 19 regression test suites
+make installcheck PG_CONFIG=/usr/bin/pg_config  # Run 22 regression test suites
 ```
 
 Requires: PostgreSQL 17 development headers, GCC, Make.
@@ -27,7 +27,7 @@ Image: `git.supported.systems/warehack.ing/pg_orrery:pg17`
 
 ## Project Layout
 ```
-pg_orrery.control                # Extension metadata (version 0.9.0)
+pg_orrery.control                # Extension metadata (version 0.12.0)
 Makefile                        # PGXS build + Docker targets
 sql/
   pg_orrery--0.1.0.sql           # v0.1.0: satellite types/functions/operators
@@ -39,6 +39,9 @@ sql/
   pg_orrery--0.7.0.sql           # v0.7.0: GiST improvements
   pg_orrery--0.8.0.sql           # v0.8.0: orbital_elements type + MPC parser (82 functions)
   pg_orrery--0.9.0.sql           # v0.9.0: equatorial type, refraction, proper motion, light-time (106 functions)
+  pg_orrery--0.10.0.sql          # v0.10.0: angular separation, cone search, apparent functions (114 functions)
+  pg_orrery--0.11.0.sql          # v0.11.0: orbital_elements constructors, moon equatorial (120 functions)
+  pg_orrery--0.12.0.sql          # v0.12.0: equatorial GiST, DE moon equatorial (132 objects)
   pg_orrery--0.1.0--0.2.0.sql    # Migration: v0.1.0 → v0.2.0 (adds solar system)
   pg_orrery--0.2.0--0.3.0.sql    # Migration: v0.2.0 → v0.3.0 (adds DE ephemeris)
   pg_orrery--0.3.0--0.4.0.sql    # Migration: v0.3.0 → v0.4.0
@@ -47,6 +50,9 @@ sql/
   pg_orrery--0.6.0--0.7.0.sql    # Migration: v0.6.0 → v0.7.0
   pg_orrery--0.7.0--0.8.0.sql    # Migration: v0.7.0 → v0.8.0 (orbital_elements type)
   pg_orrery--0.8.0--0.9.0.sql    # Migration: v0.8.0 → v0.9.0 (equatorial, refraction, proper motion, light-time)
+  pg_orrery--0.9.0--0.10.0.sql   # Migration: v0.9.0 → v0.10.0 (angular separation, cone search)
+  pg_orrery--0.10.0--0.11.0.sql  # Migration: v0.10.0 → v0.11.0 (constructors, moon equatorial)
+  pg_orrery--0.11.0--0.12.0.sql  # Migration: v0.11.0 → v0.12.0 (equatorial GiST, DE moon equatorial)
 src/
   pg_orrery.c                    # PG_MODULE_MAGIC + _PG_init() (GUC registration)
   types.h                       # All struct definitions + constants + DE body ID mapping
@@ -58,7 +64,8 @@ src/
   sgp4_funcs.c                  # sgp4_propagate(), _safe(), _series(), tle_distance()
   coord_funcs.c                 # eci_to_geodetic(), eci_to_topocentric(), ground_track()
   pass_funcs.c                  # next_pass(), predict_passes(), predict_passes_refracted(), pass_visible()
-  gist_tle.c                    # GiST operator class (&&, <->)
+  gist_tle.c                    # GiST operator class for TLE (&&, <->)
+  gist_equatorial.c              # GiST operator class for equatorial (KNN <->)
   # --- Solar System (v0.2.0) ---
   vsop87.c / vsop87.h           # VSOP87 planetary ephemeris (Bretagnon 1988)
   elp82b.c / elp82b.h           # ELP2000-82B lunar ephemeris (Chapront 1988)
@@ -83,7 +90,7 @@ src/
   # --- JPL DE Ephemeris (v0.3.0) ---
   de_reader.h / de_reader.c     # Clean-room JPL DE binary reader (Chebyshev/Clenshaw)
   eph_provider.h / eph_provider.c # Provider dispatch, GUC, lazy init, frame rotation
-  de_funcs.c                    # All _de() SQL function implementations
+  de_funcs.c                    # All _de() SQL function implementations (incl. moon equatorial DE)
   sgp4/                         # Vendored SGP4/SDP4 (Bill Gray's sat_code, MIT license)
     sgp4.c                      # Near-earth propagator (period < 225 min)
     sdp4.c                      # Deep-space propagator (period >= 225 min)
@@ -96,7 +103,7 @@ src/
     PROVENANCE.md               # Vendoring decision, modifications, verification
     LICENSE                     # MIT license (Bill Gray / Project Pluto)
 test/
-  sql/                          # 16 regression test suites
+  sql/                          # 22 regression test suites
   expected/                     # Expected output
   data/vallado_518.json         # 518 Vallado test vectors (AIAA 2006-6753-Rev1)
 docs/
@@ -123,22 +130,23 @@ All types are fixed-size, `STORAGE = plain`, `ALIGNMENT = double`. No TOAST over
 | `orbital_elements` | 72 | Classical Keplerian elements for comets/asteroids (epoch, q, e, inc, omega, Omega, tp, H, G) |
 | `equatorial` | 24 | Apparent RA (hours), Dec (degrees), distance (km) — of date |
 
-## Function Domains (114 total)
+## Function Domains (132 SQL objects)
 
 | Domain | Theory | Key Functions | Count |
 |--------|--------|---------------|-------|
 | Satellite | SGP4/SDP4 (Brouwer 1959) | `observe()`, `predict_passes()`, `eci_to_equatorial()` | 25 |
 | Planets | VSOP87 (Bretagnon 1988) | `planet_observe()`, `planet_equatorial()`, `planet_observe_apparent()` | 7 |
 | Sun/Moon | VSOP87 + ELP2000-82B | `sun_observe()`, `moon_observe()`, `sun/moon_equatorial()` | 6 |
-| Planetary moons | L1.2, TASS17, GUST86, MarsSat | `galilean_observe()`, `saturn_moon_observe()` | 4 |
+| Planetary moons | L1.2, TASS17, GUST86, MarsSat | `galilean_observe()`, `saturn_moon_observe()`, `*_equatorial()` | 12 |
 | Stars | J2000 + IAU 1976 precession | `star_observe()`, `star_equatorial()`, `star_observe_pm()` | 5 |
 | Comets/asteroids | Two-body Keplerian + MPC | `small_body_observe()`, `small_body_equatorial()`, `oe_from_mpc()` | 19 |
 | Refraction | Bennett (1982) | `atmospheric_refraction()`, `predict_passes_refracted()` | 4 |
 | Equatorial spatial | Vincenty formula | `eq_angular_distance()`, `eq_within_cone()`, `<->` | 2 |
 | Jupiter radio | Carr et al. (1983) | `jupiter_burst_probability()` | 3 |
 | Transfers | Lambert (Izzo 2015) | `lambert_transfer()`, `lambert_c3()` | 2 |
-| DE ephemeris | JPL DE440/441 (optional) | `planet_observe_de()`, `planet_equatorial_de()`, `*_apparent_de()` | 19 |
+| DE ephemeris | JPL DE440/441 (optional) | `planet_observe_de()`, `*_equatorial_de()`, `*_apparent_de()` | 23 |
-| GiST index | Altitude-band approximation | `&&` (overlap), `<->` (distance) | 8 |
+| GiST index (TLE) | Altitude-band approximation | `&&` (overlap), `<->` (distance) | 8 |
+| GiST index (equatorial) | Spherical bounding box | `<->` (KNN ordering) | 8 |
 | Diagnostics | -- | `pg_orrery_ephemeris_info()` | 1 |
 
 All functions are `PARALLEL SAFE`. VSOP87/ELP82B functions are `IMMUTABLE` (compiled-in coefficients). DE functions are `STABLE` (external file dependency).
@@ -241,6 +249,10 @@ Every `_de()` function mirrors an existing VSOP87 function:
 | `mars_moon_observe_de()` | `mars_moon_observe()` | STABLE |
 | `planet_equatorial_de()` | `planet_equatorial()` | STABLE |
 | `moon_equatorial_de()` | `moon_equatorial()` | STABLE |
+| `galilean_equatorial_de()` | `galilean_equatorial()` | STABLE |
+| `saturn_moon_equatorial_de()` | `saturn_moon_equatorial()` | STABLE |
+| `uranus_moon_equatorial_de()` | `uranus_moon_equatorial()` | STABLE |
+| `mars_moon_equatorial_de()` | `mars_moon_equatorial()` | STABLE |
 | `planet_observe_apparent_de()` | `planet_observe_apparent()` | STABLE |
 | `sun_observe_apparent_de()` | `sun_observe_apparent()` | STABLE |
 | `moon_observe_apparent_de()` | `moon_observe_apparent()` | STABLE |
@@ -268,7 +280,7 @@ All numerical logic is byte-identical to upstream. Verified against 518 Vallado
 
 ## Testing
 
-19 regression test suites via `make installcheck`:
+22 regression test suites via `make installcheck`:
 
 | Suite | What it tests |
 |-------|--------------|
@@ -276,7 +288,7 @@ All numerical logic is byte-identical to upstream. Verified against 518 Vallado
 | sgp4_propagate | SGP4/SDP4, propagation series, tle_distance |
 | coord_transforms | TEME-to-geodetic, TEME-to-topocentric, ground_track |
 | pass_prediction | predict_passes, next_pass, pass_visible, min elevation filter |
-| gist_index | `&&` overlap, `<->` distance, GiST index scan, KNN ordering |
+| gist_index | `&&` overlap, `<->` distance, GiST index scan, KNN ordering (TLE) |
 | convenience | observe(), observe_safe(), tle_from_lines(), observer_from_geodetic() |
 | star_observe | Star observation, IAU 1976 precession, heliocentric type I/O |
 | kepler_comet | Keplerian propagation (elliptic/parabolic/hyperbolic), comet_observe |
@@ -291,10 +303,13 @@ All numerical logic is byte-identical to upstream. Verified against 518 Vallado
 | refraction | Bennett refraction, P/T correction, apparent elevation, refracted pass prediction |
 | aberration | Annual aberration magnitude, DE apparent fallback, angular distance, cone search, stellar parallax |
 | vallado_518 | 518 Vallado test vectors (AIAA 2006-6753-Rev1), per-satellite breakdown |
+| v011_features | make_orbital_elements constructors, moon equatorial functions |
+| gist_equatorial | Equatorial GiST KNN ordering, RA wrapping, cone search, EXPLAIN index scan |
+| v012_features | DE moon equatorial fallback to VSOP87, invalid body_id rejection |
 
 ### PG Version Matrix
 
-Test all 19 regression suites + DE reader unit test across PostgreSQL 14-18 using Docker:
+Test all 22 regression suites + DE reader unit test across PostgreSQL 14-18 using Docker:
 
 ```bash
 make test-matrix                              # Full matrix (PG 14-18)
@@ -318,9 +333,9 @@ Logs saved to `test/matrix-logs/pg${ver}.log`. The script reuses the Dockerfile
 
 **Live:** https://pg-orrery.warehack.ing
 
-Starlight docs at `docs/` — 44 MDX pages covering all domains.
+Starlight docs at `docs/` — 44+ MDX pages covering all domains.
 
-Sections: Getting Started, Guides (9 domain walkthroughs incl. DE ephemeris), Workflow Translation (Skyfield/Horizons/GMAT/Radio Jupiter Pro comparisons), Reference (all 106 functions incl. DE variants, equatorial, refraction), Architecture (Hamilton's principles, constant custody, observation pipeline), Performance (benchmarks).
+Sections: Getting Started, Guides (9 domain walkthroughs incl. DE ephemeris), Workflow Translation (Skyfield/Horizons/GMAT/Radio Jupiter Pro comparisons), Reference (all 132 SQL objects incl. DE variants, equatorial GiST, refraction), Architecture (Hamilton's principles, constant custody, observation pipeline), Performance (benchmarks).
 
 ### Local Development
 ```bash

docs/src/content/docs/reference/functions-de.mdx

@@ -368,6 +368,122 @@ FROM moon_equatorial_de(now()) AS e;
 
 ---
 
+## galilean_equatorial_de
+
+Computes the geocentric equatorial coordinates (RA/Dec) of a Galilean moon using JPL DE ephemeris for Jupiter's position. Falls back to VSOP87 for both Jupiter and Earth when DE is unavailable. Moon offsets always come from Lieske L1.2 theory.
+
+### Signature
+
+```sql
+galilean_equatorial_de(moon_id int4, t timestamptz) → equatorial
+```
+
+### Parameters
+
+| Parameter | Type | Description |
+|-----------|------|-------------|
+| `moon_id` | `int4` | 0=Io, 1=Europa, 2=Ganymede, 3=Callisto |
+| `t` | `timestamptz` | Evaluation time |
+
+### Returns
+
+An `equatorial` with RA (hours), Dec (degrees), and distance (km) from Earth's center.
+
+### Example
+
+```sql
+-- All 4 Galilean moons via DE
+SELECT moon_id,
+       round(eq_ra(galilean_equatorial_de(moon_id, now()))::numeric, 4) AS ra,
+       round(eq_dec(galilean_equatorial_de(moon_id, now()))::numeric, 4) AS dec
+FROM generate_series(0, 3) AS moon_id;
+```
+
+---
+
+## saturn_moon_equatorial_de
+
+Computes the geocentric equatorial coordinates (RA/Dec) of a Saturn moon using JPL DE ephemeris for Saturn's position. Falls back to VSOP87 when DE is unavailable. Moon offsets come from TASS 1.7 theory.
+
+### Signature
+
+```sql
+saturn_moon_equatorial_de(moon_id int4, t timestamptz) → equatorial
+```
+
+### Parameters
+
+| Parameter | Type | Description |
+|-----------|------|-------------|
+| `moon_id` | `int4` | 0=Mimas, 1=Enceladus, 2=Tethys, 3=Dione, 4=Rhea, 5=Titan, 6=Iapetus, 7=Hyperion |
+| `t` | `timestamptz` | Evaluation time |
+
+### Example
+
+```sql
+-- Titan's position via DE
+SELECT round(eq_ra(saturn_moon_equatorial_de(5, now()))::numeric, 4) AS ra,
+       round(eq_dec(saturn_moon_equatorial_de(5, now()))::numeric, 4) AS dec;
+```
+
+---
+
+## uranus_moon_equatorial_de
+
+Computes the geocentric equatorial coordinates (RA/Dec) of a Uranus moon using JPL DE ephemeris for Uranus's position. Falls back to VSOP87 when DE is unavailable. Moon offsets come from GUST86 theory.
+
+### Signature
+
+```sql
+uranus_moon_equatorial_de(moon_id int4, t timestamptz) → equatorial
+```
+
+### Parameters
+
+| Parameter | Type | Description |
+|-----------|------|-------------|
+| `moon_id` | `int4` | 0=Miranda, 1=Ariel, 2=Umbriel, 3=Titania, 4=Oberon |
+| `t` | `timestamptz` | Evaluation time |
+
+### Example
+
+```sql
+-- Titania's position via DE
+SELECT round(eq_ra(uranus_moon_equatorial_de(3, now()))::numeric, 4) AS ra,
+       round(eq_dec(uranus_moon_equatorial_de(3, now()))::numeric, 4) AS dec;
+```
+
+---
+
+## mars_moon_equatorial_de
+
+Computes the geocentric equatorial coordinates (RA/Dec) of a Mars moon using JPL DE ephemeris for Mars's position. Falls back to VSOP87 when DE is unavailable. Moon offsets come from MarsSat analytical theory.
+
+### Signature
+
+```sql
+mars_moon_equatorial_de(moon_id int4, t timestamptz) → equatorial
+```
+
+### Parameters
+
+| Parameter | Type | Description |
+|-----------|------|-------------|
+| `moon_id` | `int4` | 0=Phobos, 1=Deimos |
+| `t` | `timestamptz` | Evaluation time |
+
+### Example
+
+```sql
+-- Both Mars moons via DE
+SELECT moon_id,
+       round(eq_ra(mars_moon_equatorial_de(moon_id, now()))::numeric, 4) AS ra,
+       round(eq_dec(mars_moon_equatorial_de(moon_id, now()))::numeric, 4) AS dec
+FROM generate_series(0, 1) AS moon_id;
+```
+
+---
+
 ## pg_orrery_ephemeris_info
 
 Returns diagnostic information about the current ephemeris provider.

docs/src/content/docs/reference/operators-gist.mdx

@@ -6,7 +6,7 @@ sidebar:
 
 import { Aside, Tabs, TabItem } from "@astrojs/starlight/components";
 
-pg_orrery defines four operators on the `tle` type and two operator classes (GiST and SP-GiST) that enable indexed satellite queries over large catalogs. The GiST index accelerates conjunction screening (orbit-to-orbit overlap). The SP-GiST index accelerates pass prediction (observer-to-orbit visibility).
+pg_orrery defines operators on the `tle` and `equatorial` types with three operator classes (two GiST + one SP-GiST) that enable indexed queries over large catalogs. The TLE GiST index accelerates conjunction screening (orbit-to-orbit overlap). The SP-GiST index accelerates pass prediction (observer-to-orbit visibility). The equatorial GiST index accelerates nearest-neighbor sky queries (angular distance KNN).
 
 ---
 
@@ -205,6 +205,81 @@ REINDEX INDEX idx_tle_gist;
 
 ---
 
+## GiST Operator Class: eq_gist_ops
+
+The `eq_gist_ops` operator class enables GiST indexing on `equatorial` columns. With this index, the `<->` operator (angular distance in degrees via the Vincenty formula) supports index-ordered KNN queries — PostgreSQL traverses the tree by increasing angular distance without computing all distances upfront.
+
+<Aside type="note">
+`eq_gist_ops` is the **DEFAULT** operator class for the `equatorial` type using GiST. No explicit operator class is needed in `CREATE INDEX`.
+</Aside>
+
+### Creating the Index
+
+```sql
+CREATE INDEX idx_sky_eq ON sky_cache USING gist (eq);
+```
+
+### What Gets Indexed
+
+The GiST index stores a 24-byte float-precision spherical bounding box for each entry:
+- **RA range:** `[ra_low, ra_high]` in radians. When `ra_low > ra_high`, the box wraps across 0h (covers `[ra_low, 2pi) union [0, ra_high]`)
+- **Dec range:** `[dec_low, dec_high]` in radians
+
+Float precision (~0.12 arcsec bounding error at RA = 2pi) is more than sufficient for index pruning. Actual angular distance is computed in double precision via the Vincenty formula during recheck.
+
+### Index-Accelerated Queries
+
+<Tabs>
+<TabItem label="KNN nearest-neighbor">
+```sql
+-- Find the 10 nearest sky objects to Jupiter
+SELECT name,
+       round((eq <-> planet_equatorial_apparent(5, NOW()))::numeric, 4) AS dist_deg
+FROM sky_cache
+ORDER BY eq <-> planet_equatorial_apparent(5, NOW())
+LIMIT 10;
+```
+</TabItem>
+<TabItem label="Cone search">
+```sql
+-- Everything within 15 degrees of Vega, sorted by distance
+SELECT name,
+       round((eq <-> star_equatorial(18.616, 38.784, NOW()))::numeric, 2) AS dist_deg
+FROM sky_cache
+WHERE eq_within_cone(eq, star_equatorial(18.616, 38.784, NOW()), 15.0)
+ORDER BY eq <-> star_equatorial(18.616, 38.784, NOW());
+```
+</TabItem>
+<TabItem label="EXPLAIN verification">
+```sql
+-- Confirm the planner uses the GiST index
+SET enable_seqscan = off;
+EXPLAIN (COSTS OFF)
+SELECT name FROM sky_cache
+ORDER BY eq <-> '(12.00000000,0.00000000,0.000)'::equatorial
+LIMIT 3;
+-- Should show: Index Scan using idx_sky_eq on sky_cache
+RESET enable_seqscan;
+```
+</TabItem>
+</Tabs>
+
+### RA Wrapping
+
+Objects near 0h (e.g., in Pisces/Aquarius) and objects near 24h are correctly identified as neighbors. The bounding box merge and distance functions handle the RA discontinuity at 0h/24h explicitly. An object at RA = 23.9h and another at RA = 0.1h are approximately 3 degrees apart (at moderate declination), and the KNN traversal finds them as neighbors.
+
+### Polar Regions
+
+Near the celestial poles (Dec approaching +/-90 degrees), RA becomes degenerate — a small patch of sky spans a wide RA range. Bounding boxes for polar objects may cover the full RA circle. This does not affect **correctness** (the Vincenty formula handles pole convergence naturally) but can degrade **index selectivity** for dense polar catalogs. For typical sky catalogs (<10,000 objects), the effect is negligible.
+
+### Design Notes
+
+- **KNN only** (strategy 15, `<->` ordering). No `&&` overlap operator — meaningless for point types.
+- **Distance unit:** degrees, matching `eq_angular_distance()`.
+- **Lower-bound contract hardened:** box boundaries widened by float epsilon before distance computation to guarantee KNN correctness under float-to-double promotion.
+
+---
+
 ### &? (Visibility Cone)
 
 Tests whether a satellite could possibly be visible from a ground observer during a time window. This is a geometric superset filter -- it may include satellites that do not produce an actual pass (false positives), but will never exclude one that does (no false negatives).