feat: 引入可切换星历模型并扩展天象观测链路

- 新增半解析、旧模型、自定义与多源堆叠星历实例，提供 Context、Instance、SPK 读取及状态与视位置计算
- 统一太阳、月球和行星实例接口，扩展黄经穿越、留、相位、最近角距、偕日可见、任意高度升落、轨道节点及凌日等天象查询
- 完善日月食、月掩与凌日的月缘剖面、有限盘面接触、站心修正、局地可见性、全球路径和地图输出
- 新增 SVG、GeoJSON、KML 天象输出及凌日、月掩和月缘地形相关缓存与几何求解
- 新增恒星星表导入与查询，支持 CSV、Hipparcos、BSC5、Stellarium 等格式及名称、交叉标识、锥面检索和星等过滤
- 补充 IAU 2006、地球定向、折射消光、大气观测、轨道传播及半解析行星/月球数据支持
- 将默认未来民用时标切换为 TimeScaleLeapHour，更新 2027–2400 农历速查表、中文日期解析和时区边界处理
- 增加事件基线、跨模型回归、几何边界、月缘地形和输出契约测试，完善中英文手册、示例资源、NOTICE 与忽略规则

basic/solar_eclipse_hybrid_envelope.go

@@ -1,6 +1,10 @@
 package basic
 
-import "math"
+import (
+	"math"
+
+	"b612.me/astro/internal/geodata"
+)
 
 // Absolute Julian dates quantize a moving sky position at about 1e-10 radians.
 const solarEclipseCentralVectorTolerance = 2e-10
@@ -20,8 +24,8 @@ func solarCentralBandSkyOffset(context localSolarEclipseStateContext, longitude,
 	equatorial := math.Hypot(sun[0], sun[1])
 	east := [3]float64{-sun[1] / equatorial, sun[0] / equatorial, 0}
 	north := [3]float64{-sun[2] * east[1], sun[2] * east[0], equatorial}
-	radius := math.Asin(solarEclipseEarthEquatorialRadiusKM*context.params.umbralK*localSolarMoonRadiusScale/moonDistance) -
-		math.Asin(solarEclipseEarthEquatorialRadiusKM*context.params.sunRadiusRatio/sunDistance)
+	radius := math.Asin(geodata.EarthEquatorialRadiusKM*context.params.umbralK*localSolarMoonRadiusScale/moonDistance) -
+		math.Asin(geodata.EarthEquatorialRadiusKM*context.params.sunRadiusRatio/sunDistance)
 	return [3]float64{dotSolarEclipse3(moon, east), dotSolarEclipse3(moon, north), math.Sin(radius)}
 }
 
@@ -96,7 +100,7 @@ func (solver solarEclipseSolver) correctCentralBandVectorBoundary(predictor, tan
 			state := evaluation.center.stateAt(coordinates[0]*rad, coordinates[1]*rad, 0)
 			return solarEclipseNonCentralBandState{
 				coordinates: coordinates, tangent: nextTangent,
-				point: SolarEclipsePathPoint{JDE: jde, Longitude: normalizeLongitude(coordinates[0]), Latitude: coordinates[1], SunAltitude: state.sunAltitudeRad / rad},
+				point: SolarEclipsePathPoint{JDE: jde, Longitude: geodata.NormalizeLongitude(coordinates[0]), Latitude: coordinates[1], SunAltitude: state.sunAltitudeRad / rad},
 			}, valid
 		}
 		delta, valid := solveSolarEclipse3x3([3][3]float64{jacobian[0], jacobian[1], tangent}, [3]float64{-residual[0], -residual[1], -plane})
@@ -257,7 +261,7 @@ func (solver solarEclipseSolver) hybridCentralBandTransition(seed SolarEclipsePa
 		residual := solarCentralBandSkyOffset(context, coordinates[0], coordinates[1])
 		if math.Hypot(residual[0], residual[1]) < solarEclipseCentralVectorTolerance/2 && math.Abs(residual[2]) < 1e-12 {
 			state := context.stateAt(coordinates[0]*rad, coordinates[1]*rad, 0)
-			return SolarEclipsePathPoint{JDE: jde, Longitude: normalizeLongitude(coordinates[0]), Latitude: coordinates[1], SunAltitude: state.sunAltitudeRad / rad}, true
+			return SolarEclipsePathPoint{JDE: jde, Longitude: geodata.NormalizeLongitude(coordinates[0]), Latitude: coordinates[1], SunAltitude: state.sunAltitudeRad / rad}, true
 		}
 		var jacobian [3][3]float64
 		for column := range coordinates {
@@ -305,7 +309,7 @@ func (solver solarEclipseSolver) centralBandVectorHorizonRoots(axisContactJDE, d
 			context := solver.localStateContextAt(jde)
 			state := context.stateAt(coordinates[0]*rad, coordinates[1]*rad, 0)
 			if math.Hypot(residual[0], residual[1]) <= solarEclipseCentralVectorTolerance && math.Abs(state.sunAltitudeRad) < 1e-8 {
-				roots[i] = SolarEclipsePathPoint{JDE: jde, Longitude: normalizeLongitude(coordinates[0]), Latitude: coordinates[1], SunAltitude: state.sunAltitudeRad / rad}
+				roots[i] = SolarEclipsePathPoint{JDE: jde, Longitude: geodata.NormalizeLongitude(coordinates[0]), Latitude: coordinates[1], SunAltitude: state.sunAltitudeRad / rad}
 				// Grazing horizon roots can be many minutes from axis contact.
 				// Bound them by the shadow's limb-crossing interval, not a fixed
 				// window around the seed.