feat: 完善时标与天象几何计算并扩展输出接口

- 新增时标、ΔT 模型、质心时间与 UT1 支持
- 改进日月食、月掩、行星事件及路径边界计算
- 完善恒星三维自行与动态距离传播
- 扩展 SVG、GeoJSON、KML 输出与底层距离换算工具
- 整理中英文手册、示例资源及回归测试

internal/lunarhorizon/lunarhorizon.go

@@ -64,11 +64,11 @@ func RefineWithin(points []geodata.GeoPoint, at time.Time, toleranceDegrees floa
 	if len(points) < 3 {
 		return points
 	}
-	jd := basic.Date2JDE(at.UTC())
-	tt := basic.TD2UT(jd, true)
+	jd := basic.Date2JD(at.UTC())
+	tt := basic.UTC2TT(jd)
 	ra, dec := basic.HMoonTrueRaDec(tt)
 	distanceAU := basic.HMoonAway(tt) / 149597870.7
-	sidereal := basic.ApparentSiderealTime(jd) * 15
+	sidereal := basic.ApparentSiderealTime(basic.UTC2UT1(jd)) * 15
 	center := geodata.GeoPoint{Longitude: normalizeLongitude(ra - sidereal), Latitude: dec}
 	// Every correction is at the same instant. Reuse its full ephemeris while
 	// retaining the ellipsoid and topocentric transform used by HMoonHeight.