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

moon/svg/occultation_planet.go

@@ -7,6 +7,7 @@ import (
 	"strings"
 	"time"
 
+	"b612.me/astro"
 	"b612.me/astro/internal/geodata"
 	"b612.me/astro/internal/occultationgeo"
 	"b612.me/astro/internal/svgmap"
@@ -59,9 +60,16 @@ func PlanetOccultationPathSVG(
 	path moon.PlanetOccultationPath,
 	options PlanetOccultationSVGOptions,
 ) (string, error) {
+	if options.TimeScale == astro.TimeScaleUT1 && options.Location != nil && options.Location != time.UTC {
+		return "", fmt.Errorf("occultation SVG: UT1 labels do not take a non-UTC location")
+	}
 	if err := validatePlanetOccultationPath(path); err != nil {
 		return "", err
 	}
+	if options.TimeScale == astro.TimeScaleUT1 {
+		options.Location = time.UTC
+		path = moon.PlanetOccultationPathInUT1(path)
+	}
 	targetID := path.TargetID
 	if targetID == "" {
 		targetID = path.Planet.String()