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/solar_eclipse_polar_envelope_test.go

@@ -15,7 +15,7 @@ func TestSolarEclipsePolarCentralEnvelope(t *testing.T) {
 		{2026, 2, 17, RiseSetDirectionSet},
 	} {
 		t.Run(fmt.Sprintf("%04d-%02d-%02d", sample.year, sample.month, sample.day), func(t *testing.T) {
-			seed := JDECalc(sample.year, sample.month, float64(sample.day))
+			seed := JDCalc(sample.year, sample.month, float64(sample.day))
 			result := SolarEclipsePartialFootprints(seed, SolarEclipsePartialFootprintOptions{
 				StepDays: 2.0 / 1440, BoundaryPoints: 96,
 			})