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/occultation_star_diagram.go

@@ -67,13 +67,11 @@ type starOccultationDiagramTime struct {
 	labels []string
 }
 
-// StarOccultationDiagram 为已求解的固定地点恒星月掩计算以月心为原点的切平面轨迹。事件数据无效或不完整时，结果不含帧。
-// StarOccultationDiagram computes a Moon-centered tangent-plane track for an already solved fixed-site stellar occultation. Invalid or incomplete event data produces a result without frames.
-func StarOccultationDiagram(
+// StarOccultationDiagramWithInstance 用指定星历实例求值；inst 为 nil 时用进程当前模型 / evaluation with an explicit instance; nil uses the process model.
+func StarOccultationDiagramWithInstance(
 	info StarOccultationInfo,
 	star StarCoordinate,
-	options StarOccultationDiagramOptions,
-) StarOccultationDiagramResult {
+	options StarOccultationDiagramOptions, inst *Instance) StarOccultationDiagramResult {
 	options = normalizeStarOccultationDiagramOptions(options)
 	result := StarOccultationDiagramResult{Occultation: info, StepDays: options.StepDays}
 	if star.Validate() != nil || info.Observer.Validate() != nil ||
@@ -86,9 +84,9 @@ func StarOccultationDiagram(
 	startTT := occultationTimeToTT(info.Immersion)
 	greatestTT := occultationTimeToTT(info.Greatest)
 	endTT := occultationTimeToTT(info.Emersion)
-	immersionFrame, immersionOK := starOccultationDiagramFrameAt(startTT, star, info.Observer)
-	greatestFrame, greatestOK := starOccultationDiagramFrameAt(greatestTT, star, info.Observer)
-	emersionFrame, emersionOK := starOccultationDiagramFrameAt(endTT, star, info.Observer)
+	immersionFrame, immersionOK := starOccultationDiagramFrameAt(startTT, star, info.Observer, inst)
+	greatestFrame, greatestOK := starOccultationDiagramFrameAt(greatestTT, star, info.Observer, inst)
+	emersionFrame, emersionOK := starOccultationDiagramFrameAt(endTT, star, info.Observer, inst)
 	if !immersionOK || !greatestOK || !emersionOK ||
 		!starOccultationDiagramMatchesInfo(info, immersionFrame, greatestFrame, emersionFrame) {
 		return result
@@ -97,7 +95,7 @@ func StarOccultationDiagram(
 	result.StepDays = stepDays
 	result.Frames = make([]StarOccultationDiagramFrame, 0, len(times))
 	for _, item := range times {
-		frame, ok := starOccultationDiagramFrameAt(item.jde, star, info.Observer)
+		frame, ok := starOccultationDiagramFrameAt(item.jde, star, info.Observer, inst)
 		if !ok {
 			return StarOccultationDiagramResult{Occultation: info, StepDays: stepDays}
 		}
@@ -116,8 +114,9 @@ func starOccultationDiagramMatchesInfo(
 		!finite(info.PositionAngleDeg) {
 		return false
 	}
-	if math.Abs(immersion.SeparationArcsec-immersion.MoonRadiusArcsec) > starOccultationDiagramGeometryArcsec ||
-		math.Abs(emersion.SeparationArcsec-emersion.MoonRadiusArcsec) > starOccultationDiagramGeometryArcsec {
+	// 已按月缘剖面收敛的接触不在圆月面上，圆月面接触判据只适用于未修正的结果。
+	if !info.LunarLimbApplied && (math.Abs(immersion.SeparationArcsec-immersion.MoonRadiusArcsec) > starOccultationDiagramGeometryArcsec ||
+		math.Abs(emersion.SeparationArcsec-emersion.MoonRadiusArcsec) > starOccultationDiagramGeometryArcsec) {
 		return false
 	}
 	return math.Abs(greatest.SeparationArcsec-info.MinimumSeparationArcsec) <= starOccultationDiagramGeometryArcsec &&
@@ -221,9 +220,11 @@ func starOccultationDiagramLabelPriority(labels []string) int {
 	}
 }
 
-func starOccultationDiagramFrameAt(tt float64, star StarCoordinate, observer Observer) (StarOccultationDiagramFrame, bool) {
-	position := starMoonPositionAt(tt, star, observer)
-	moonRadius := moonTopocentricSemidiameterN(tt, observer, -1)
+func starOccultationDiagramFrameAt(tt float64, star StarCoordinate, observer Observer, instances ...*Instance) (StarOccultationDiagramFrame, bool) {
+	inst := instanceValue(instances)
+
+	position := starMoonPositionAt(tt, star, observer, inst)
+	moonRadius := moonTopocentricSemidiameterN(tt, observer, -1, inst)
 	if !position.valid || !finite(moonRadius) || moonRadius <= 0 {
 		return StarOccultationDiagramFrame{}, false
 	}