feat: catálogo de estrelas embutido (Yale BSC, V<=5.5, 2887 estrelas)

tools/build_catalog.py baixa o bsc5-short.json, converte RA/Dec/V/K e
emite starcatalog.js compacto (65KB) com paleta de cores por
temperatura (corpo negro dessaturado).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015HtPHsTnDcLVSCiF5FGHZj

tools/build_catalog.py

@@ -0,0 +1,117 @@
+#!/usr/bin/env python3
+"""Gera plugin/contents/ui/starcatalog.js a partir do Yale Bright Star Catalog.
+
+Baixa bsc5-short.json (RA/Dec/V/K), filtra V <= MAG_LIMIT, converte a
+temperatura de cor em RGB (aprox. corpo negro, quantizada numa paleta pequena)
+e emite um JS compacto:
+
+    const STAR_PALETTE = [[r,g,b], ...];
+    const STAR_DATA    = [[raDeg, decDeg, vmag, colorIdx], ...];  // ordenado por mag
+
+Uso: python3 tools/build_catalog.py
+"""
+
+import json
+import math
+import re
+import urllib.request
+from pathlib import Path
+
+URL = "https://raw.githubusercontent.com/brettonw/YaleBrightStarCatalog/master/bsc5-short.json"
+OUT = Path(__file__).resolve().parent.parent / "plugin/contents/ui/starcatalog.js"
+MAG_LIMIT = 5.5
+
+# Limites (K) e centro representativo de cada faixa de temperatura
+TEMP_BINS = [
+    (0,     3500,  3000),   # M — alaranjado-avermelhado
+    (3500,  4500,  4000),   # K — laranja
+    (4500,  5500,  5000),   # G — amarelo-branco
+    (5500,  6500,  6000),   # F — branco-amarelado
+    (6500,  8000,  7200),   # A — branco
+    (8000,  11000, 9500),   # B tardio — branco-azulado
+    (11000, 16000, 13000),  # B — azul-branco
+    (16000, 10**9, 20000),  # O/B quente — azul
+]
+SATURATION = 0.6  # estrelas reais parecem quase brancas; 1.0 = cor plena
+
+
+def blackbody_rgb(kelvin: float) -> tuple[int, int, int]:
+    """Aproximação de Tanner Helland (válida ~1000K-40000K)."""
+    t = kelvin / 100.0
+    if t <= 66:
+        r = 255.0
+        g = 99.4708025861 * math.log(t) - 161.1195681661
+        b = 0.0 if t <= 19 else 138.5177312231 * math.log(t - 10) - 305.0447927307
+    else:
+        r = 329.698727446 * (t - 60) ** -0.1332047592
+        g = 288.1221695283 * (t - 60) ** -0.0755148492
+        b = 255.0
+    def clamp(x):
+        return max(0, min(255, round(x)))
+    return clamp(r), clamp(g), clamp(b)
+
+
+def desaturate(rgb, amount):
+    r, g, b = rgb
+    lum = 0.2126 * r + 0.7152 * g + 0.0722 * b
+    mix = lambda c: round(lum + (c - lum) * amount)
+    return mix(r), mix(g), mix(b)
+
+
+def parse_ra(s: str) -> float:
+    m = re.match(r"(\d+)h\s*(\d+)m\s*([\d.]+)s", s)
+    h, mi, se = float(m.group(1)), float(m.group(2)), float(m.group(3))
+    return (h + mi / 60 + se / 3600) * 15.0
+
+
+def parse_dec(s: str) -> float:
+    m = re.match(r"([+-])(\d+)°\s*(\d+)′\s*([\d.]+)″", s)
+    sign = -1.0 if m.group(1) == "-" else 1.0
+    d, mi, se = float(m.group(2)), float(m.group(3)), float(m.group(4))
+    return sign * (d + mi / 60 + se / 3600)
+
+
+def temp_index(kelvin: float) -> int:
+    for i, (lo, hi, _) in enumerate(TEMP_BINS):
+        if lo <= kelvin < hi:
+            return i
+    return len(TEMP_BINS) - 1
+
+
+def main():
+    raw = json.loads(urllib.request.urlopen(URL, timeout=30).read())
+    stars = []
+    for entry in raw:
+        if "V" not in entry or "RA" not in entry or "Dec" not in entry:
+            continue
+        vmag = float(entry["V"])
+        if vmag > MAG_LIMIT:
+            continue
+        kelvin = float(entry.get("K", 6000))
+        stars.append((
+            round(parse_ra(entry["RA"]), 2),
+            round(parse_dec(entry["Dec"]), 2),
+            round(vmag, 2),
+            temp_index(kelvin),
+        ))
+
+    stars.sort(key=lambda s: s[2])  # mais brilhantes primeiro
+
+    palette = [desaturate(blackbody_rgb(center), SATURATION)
+               for _, _, center in TEMP_BINS]
+
+    rows = ",\n".join(
+        f"[{ra},{dec},{mag},{ci}]" for ra, dec, mag, ci in stars
+    )
+    OUT.write_text(
+        "/* Gerado por tools/build_catalog.py — NÃO editar à mão.\n"
+        f"   Yale Bright Star Catalog, V <= {MAG_LIMIT}, {len(stars)} estrelas.\n"
+        "   Formato: [raGraus, decGraus, magV, idxPaleta] ordenado por magnitude. */\n"
+        f"const STAR_PALETTE = {json.dumps([list(p) for p in palette])};\n"
+        f"const STAR_DATA = [\n{rows}\n];\n"
+    )
+    print(f"{len(stars)} estrelas -> {OUT} ({OUT.stat().st_size / 1024:.0f} KB)")
+
+
+if __name__ == "__main__":
+    main()