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

basic/planet_phase_test.go

@@ -7,14 +7,14 @@ import (
 )
 
 func TestVenusIlluminatedFractionMeeusExample(t *testing.T) {
-	jd := Date2JDE(time.Date(1992, 12, 20, 0, 0, 0, 0, time.UTC))
+	jd := Date2JD(time.Date(1992, 12, 20, 0, 0, 0, 0, time.UTC))
 
 	assertPlanetPhaseClose(t, "VenusPhaseAngle", VenusPhaseAngle(jd), 72.96, 0.01)
 	assertPlanetPhaseClose(t, "VenusIlluminatedFraction", VenusIlluminatedFraction(jd), 0.647, 0.001)
 }
 
 func TestPlanetIlluminatedFractionRanges(t *testing.T) {
-	jd := TD2UT(Date2JDE(time.Date(2026, 4, 26, 9, 30, 45, 0, time.UTC)), true)
+	jd := UTC2TT(Date2JD(time.Date(2026, 4, 26, 9, 30, 45, 0, time.UTC)))
 	cases := []struct {
 		name          string
 		phaseAngle    func(float64) float64