Merge the solar-system branch, so the star catalogue lands on the sky it now shares

Both branches changed the system view's star, the body card's provenance line, the exoplanet
fetch and the ETL's validators. Resolved by keeping both sides:

- The system view's star is the catalogue's (its own radius and temperature, a limb-darkened
  surface in its colour) and turns like a planet when it is the Sun (the solar branch's IAU pole
  and 25.38-day turn), keyed on SUN_STAR_ID, since the catalogue branch dropped the scene's own
  SOL_STAR_ID. Framing takes the outermost thing drawn (an eccentric orbit's aphelion, from the
  solar branch) and the star's radius for a giant (from the catalogue). The solar branch's comment
  about a halo is dropped: there has been none since #33.
- The card's no-temperature sentence is the catalogue's (the host's luminosity or the orbit's size,
  not "not in the catalogue", which holds for 27 planets) and ends with the solar branch's reason
  why no image is used (a point of light for the 101 imaged planets, none for the rest).
- fetchExoplanets reads the composite table and the distance errors (catalogue) and the imaged
  list (solar); build.ts runs both branches' validators.

The data were regenerated by the full ETL on the merged code, from cache (nothing refetched):
stars.bin, stars-meta.bin, stars-index.json and deepsky.json come out byte for byte the catalogue
branch's, bodies.json the solar branch's, and exoplanets.json the catalogue branch's but for the
imaged flag on 101 planets, WASP-108 b not among them. Unit suite 977 passed, the two branches'
870 and 837 over their shared 730, so no test was lost.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

README.md

@@ -53,9 +53,19 @@ in it is measured and what is not.
 ![The solar system: orbit ellipses over a dashed reference grid marking 5 AU rings out to 35 AU](docs/screenshots/system-view.jpg)
 
 **System view** — selecting a star flies the camera continuously into its system rather than
-cutting to a new scene. The Sun gets the real solar-system bodies from JPL Horizons; other
+cutting to a new scene. The Sun gets the real solar-system bodies, moving on JPL's mean orbital
+elements — Standish's for the planets, JPL SSD's satellite table for the moons, the Small-Body
+Database for Ceres, Eris, Haumea and Makemake — and turned by the IAU's rotational elements
+(Eris, Haumea, Makemake and Nereid, which have none, at their measured days about their orbit
+normals, and Hyperion, which tumbles, not at all), Earth by the IERS Earth Rotation Angle; a
+tidally locked moon's prime meridian turns at its JPL mean motion, and its pole's terms that turn
+within 5 per cent of a multiple of its node's rate at that multiple of its JPL node rate, both
+re-phased to the IAU's values on 2025-01-01 (the Moon's and Phobos's are left as the IAU has them,
+and so are the circles Ariel's, Umbriel's, Titania's and Oberon's poles go round on, at rates none
+of their nodes has), and Iapetus's pole follows its orbit normal
+(`lockedToOrbit`), so each keeps its face to its planet from AD 1 to 3000; other
 stars get their confirmed exoplanets. Orbits are drawn as ellipses and bodies are propagated
-along them by a Kepler solver against the current epoch. Under them, a dashed grid marks out
+along them by a Kepler solver to the date on the map's clock. Under them, a dashed grid marks out
 round distances in AU — 5 AU rings for the solar system, 0.01 AU rings for TRAPPIST-1 — with a
 drop line from each body, so eccentricity and inclination read against a circular reference
 instead of having to be inferred from a shape in space. The camera frames that grid rather than
@@ -113,7 +123,8 @@ its own readout, so a stale image is visible as one.
   both backends. Their size is angular rather than world-space — real stars are unresolvable
   point sources, so apparent size should follow brightness, not distance.
 - **One reference frame, from three sources.** HYG gives star positions in equatorial J2000.
-  JPL Horizons reports orbital elements against the ecliptic, tilted 23.4° away. The Exoplanet
+  JPL gives the planets' orbital elements against the ecliptic, tilted 23.4° away, and the moons'
+  against the ecliptic (the Moon), a Laplace plane, or their planet's equator (Uranus's and Pluto's). The Exoplanet
   Archive measures inclination from the *plane of the sky* — perpendicular to our line of sight
   to each host star, which is why transiting planets cluster at 90°. Each set of elements is
   rotated from its own reference plane into the scene's equatorial frame, so a direction means
@@ -138,9 +149,11 @@ its own readout, so a stale image is visible as one.
 
 ### On surfaces that were never photographed
 
-Fifteen bodies here have a real photograph. Everything else does not, and never will on current
-instruments: no exoplanet's surface has ever been imaged, and a few of the solar system's own
-moons have no usable map in this asset set either.
+Twenty-eight bodies here are wrapped in real photography: the Sun, the eight planets and the Moon,
+and eighteen moons and dwarf planets in mission mosaics, grey where no probe has seen them
+(`src/assets/textures/README.md`). Everything else is not, and no exoplanet ever will be on
+current instruments: none has had its surface imaged. The five large moons of Uranus and a few
+small bodies have no map in this asset set either.
 
 Those bodies get a surface reasoned from what *has* been measured, in a chain that is worth
 following because every link is standard:
@@ -204,7 +217,7 @@ re-runs are cheap and offline-friendly; set `ETL_FORCE_REFRESH=1` to bypass the
 | Script | Source | Output |
 | --- | --- | --- |
 | `fetchStars.ts` | HYG database, plus any other positional catalogue wired in (see below) | the catalogue stars, handed to `fetchExoplanets.ts` |
-| `fetchSolarSystem.ts` | JPL Horizons / SSD | `bodies.json` |
+| `fetchSolarSystem.ts` | JPL SSD mean elements (Standish's planets, the satellite table), the Small-Body Database, NAIF's PCK, JPL Horizons | `bodies.json` |
 | `fetchExoplanets.ts` | NASA Exoplanet Archive (TAP), and the stars above with the hosts it adds | `exoplanets.json`, `stars.bin`, `stars-meta.bin`, `stars-index.json` |
 | `fetchDeepSky.ts` | OpenNGC | `deepsky.json` |
 
@@ -330,7 +343,7 @@ plugin's own files are kept so it can be listed from a marketplace of its own la
 ## Data credits
 
 Star catalogue: [HYG database](https://github.com/astronexus/HYG-Database) (Hipparcos, Yale
-Bright Star, Gliese) — 68 388 stars within 250 pc. Solar-system ephemerides: NASA/JPL Horizons. Exoplanets: NASA Exoplanet
+Bright Star, Gliese) — 68 388 stars within 250 pc. Solar-system orbits: JPL approximate planetary mean elements (Standish), JPL SSD satellite mean elements and the JPL Small-Body Database; rotation: the IAU WGCCRE 2015 report via NAIF's pck00011, with a locked moon's W and its pole's terms within 5 per cent of its node's rate re-rated to its JPL mean elements (but the Moon's and Phobos's) and Iapetus's pole carried round its orbit normal, and for Earth the IERS Conventions 2010; physical data, and the positions the orbits are checked against: NASA/JPL Horizons. Exoplanets: NASA Exoplanet
 Archive. Deep-sky objects: [OpenNGC](https://github.com/mattiaverga/OpenNGC). Body and skybox
 imagery: NASA/JPL/USGS public domain and Solar System Scope (CC BY 4.0) — per-file provenance
-is recorded in `src/app/shared/rendering/texture-catalog.ts`.
+is recorded in `src/assets/textures/README.md`.