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

geojson/api_default.go

@@ -0,0 +1,84 @@
+package geojson
+
+import (
+	eclipsecore "b612.me/astro/eclipse"
+	"b612.me/astro/mercury"
+	"b612.me/astro/venus"
+)
+
+// MarshalLunarEclipse 将月食 P1/P4 站心月心可见区、几何地平线以及 P1-P4 的时间包络编码为 GeoJSON，不含折射。
+// MarshalLunarEclipse encodes the P1/P4 topocentric Moon-center visibility regions, their geometric horizons and the P1-P4 time envelopes, without refraction.
+// boundaryPoints 小于等于零时使用 360；其他值限制在 [12, 1440]。
+// boundaryPoints values <= 0 use 360; other values are clamped to [12, 1440].
+func MarshalLunarEclipse(info eclipsecore.LunarEclipseInfo, boundaryPoints int) ([]byte, error) {
+	return defaultModule.MarshalLunarEclipse(info, boundaryPoints)
+}
+
+// MarshalLunarEclipseWithOptions 编码月食，输出内容与采样精度由 options 选择。
+// MarshalLunarEclipseWithOptions encodes a lunar eclipse with the content and sampling selected by options.
+func MarshalLunarEclipseWithOptions(
+	info eclipsecore.LunarEclipseInfo,
+	boundaryPoints int,
+	options LunarEclipseOptions,
+) ([]byte, error) {
+	return defaultModule.MarshalLunarEclipseWithOptions(info, boundaryPoints, options)
+}
+
+// MarshalLunarEclipseWithTimeMarkers 编码月食，并沿半影开始到结束的月下点轨迹追加 Point 要素。
+// MarshalLunarEclipseWithTimeMarkers encodes a lunar eclipse and adds Point Features along the sublunar track from penumbral start through end.
+// 已有要素保持不变；标记标签使用 options.Location，时间值保持 UTC。
+// Existing features are unchanged; marker labels use options.Location while time values stay UTC.
+func MarshalLunarEclipseWithTimeMarkers(
+	info eclipsecore.LunarEclipseInfo,
+	boundaryPoints int,
+	options TimeMarkerOptions,
+) ([]byte, error) {
+	return defaultModule.MarshalLunarEclipseWithTimeMarkers(info, boundaryPoints, options)
+}
+
+// MarshalSolarEclipse 将日食半影足迹和可选中心食带编码为 GeoJSON。
+// MarshalSolarEclipse encodes penumbral footprints and an optional central path as GeoJSON.
+func MarshalSolarEclipse(
+	partial eclipsecore.SolarEclipsePartialFootprintsInfo,
+	central *eclipsecore.SolarEclipsePath,
+) ([]byte, error) {
+	return defaultModule.MarshalSolarEclipse(partial, central)
+}
+
+// MarshalSolarEclipseShadowInstant 单时刻阴影足迹的最小 GeoJSON：只含该时刻的区域与物理边界 / one instant as the smallest useful GeoJSON.
+func MarshalSolarEclipseShadowInstant(
+	instant eclipsecore.SolarEclipseShadowInstant,
+) ([]byte, error) {
+	return defaultModule.MarshalSolarEclipseShadowInstant(instant)
+}
+
+// MarshalSolarEclipseWithOptions 编码日食，输出内容由 options 选择 / encodes a solar eclipse with the content selected by options.
+func MarshalSolarEclipseWithOptions(
+	partial eclipsecore.SolarEclipsePartialFootprintsInfo,
+	central *eclipsecore.SolarEclipsePath,
+	options SolarEclipseOptions,
+) ([]byte, error) {
+	return defaultModule.MarshalSolarEclipseWithOptions(partial, central, options)
+}
+
+// MarshalSolarEclipseWithTimeMarkers 编码日食，并沿中心线按固定间隔追加 Point 要素；已有要素不变，标记标签使用 options.Location，时间值保持 UTC。
+// MarshalSolarEclipseWithTimeMarkers encodes a solar eclipse and adds Point Features at regular intervals along the central line. Existing features are unchanged; marker labels use options.Location while time values stay UTC.
+func MarshalSolarEclipseWithTimeMarkers(
+	partial eclipsecore.SolarEclipsePartialFootprintsInfo,
+	central *eclipsecore.SolarEclipsePath,
+	options TimeMarkerOptions,
+) ([]byte, error) {
+	return defaultModule.MarshalSolarEclipseWithTimeMarkers(partial, central, options)
+}
+
+// MarshalMercuryTransit 将水星凌日的全球可见分区、一触/四触视地平线与可选站心接触等时线编码为 GeoJSON。
+// MarshalMercuryTransit encodes the global visibility regions, C1/C4 apparent horizons and optional topocentric contact isochrones of a Mercury transit.
+func MarshalMercuryTransit(info mercury.TransitInfo, options PlanetTransitOptions) ([]byte, error) {
+	return defaultModule.MarshalMercuryTransit(info, options)
+}
+
+// MarshalVenusTransit 将金星凌日的全球可见分区、一触/四触视地平线与可选站心接触等时线编码为 GeoJSON。
+// MarshalVenusTransit encodes the global visibility regions, C1/C4 apparent horizons and optional topocentric contact isochrones of a Venus transit.
+func MarshalVenusTransit(info venus.TransitInfo, options PlanetTransitOptions) ([]byte, error) {
+	return defaultModule.MarshalVenusTransit(info, options)
+}