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

mercury/transit.go

@@ -32,18 +32,18 @@ type TransitInfo struct {
 }
 
 // NextTransit 下一次地心水星凌日 / next geocentric Mercury transit.
-func NextTransit(date time.Time) TransitInfo {
-	return transitInfoFromBasic(basic.NextMercuryTransit(basic.Date2JD(date.UTC())), date.Location())
+func (module *Mercury) NextTransit(date time.Time) TransitInfo {
+	return transitInfoFromBasic(basic.NextMercuryTransitWithInstance(basic.Date2JD(date.UTC()), module.inst), date.Location())
 }
 
 // LastTransit 上一次地心水星凌日 / previous geocentric Mercury transit.
-func LastTransit(date time.Time) TransitInfo {
-	return transitInfoFromBasic(basic.LastMercuryTransit(basic.Date2JD(date.UTC())), date.Location())
+func (module *Mercury) LastTransit(date time.Time) TransitInfo {
+	return transitInfoFromBasic(basic.LastMercuryTransitWithInstance(basic.Date2JD(date.UTC()), module.inst), date.Location())
 }
 
 // ClosestTransit 最近一次地心水星凌日 / closest geocentric Mercury transit.
-func ClosestTransit(date time.Time) TransitInfo {
-	return transitInfoFromBasic(basic.ClosestMercuryTransit(basic.Date2JD(date.UTC())), date.Location())
+func (module *Mercury) ClosestTransit(date time.Time) TransitInfo {
+	return transitInfoFromBasic(basic.ClosestMercuryTransitWithInstance(basic.Date2JD(date.UTC()), module.inst), date.Location())
 }
 
 func transitInfoFromBasic(result basic.PlanetTransitResult, loc *time.Location) TransitInfo {
@@ -71,3 +71,26 @@ func transitInfoFromBasic(result basic.PlanetTransitResult, loc *time.Location)
 	}
 	return info
 }
+
+// LocalTransitInfo 站心水星凌日信息 / topocentric Mercury transit information.
+//
+// 时刻保持调用者传入的 TransitInfo 的时区；太阳高度为几何中心高度，不含折射。
+// Times keep the timezone of the supplied TransitInfo; Sun altitudes are geometric centre altitudes without refraction.
+type LocalTransitInfo = basic.PlanetTransitLocalInfo
+
+// LocalTransitContact 站心凌日接触 / topocentric transit contact.
+type LocalTransitContact = basic.PlanetTransitLocalContactInfo
+
+// LocalTransit 地心凌日 transit 在观测地的站心接触与凌甚 / topocentric contacts of transit seen from the site.
+//
+// lon、lat 为度，东经、北纬为正；height 为海拔米。
+// lon and lat are in degrees, east and north positive; height is in meters.
+func (module *Mercury) LocalTransit(transit TransitInfo, lon, lat, height float64) LocalTransitInfo {
+	if !transit.Valid {
+		return LocalTransitInfo{}
+	}
+	result := basic.PlanetTransitResultFromTimes(1,
+		transit.Start, transit.InternalStart, transit.Greatest, transit.InternalEnd, transit.End)
+	local := basic.PlanetTransitLocalWithInstance(result, basic.Observer{Longitude: lon, Latitude: lat, Height: height}, module.inst)
+	return basic.PlanetTransitLocalInfoFromResult(local, transit.Greatest.Location())
+}