feat: 增强日月食搜索、沙罗周期与内行星凌日

- 使用压缩表加速查找日月食沙罗周期信息
- 优化日月食搜索跳步，减少非食季朔望月扫描
- 新增本地日全食、日环食、月全食搜索接口，返回 ok 区分未找到结果
- 新增水星、金星地心凌日查询及测试

eclipse/search_skip.go

@@ -0,0 +1,36 @@
+package eclipse
+
+import (
+	"math"
+
+	"b612.me/astro/basic"
+)
+
+const (
+	eclipseSeasonNodeDistanceLimitDeg = 35.0
+	eclipseSeasonMaxSearchStep        = 4
+)
+
+func nextEclipseSearchCandidateTT(candidateTT float64, phaseType, direction int, synodicMonthDays float64) float64 {
+	step := eclipseSearchStep(candidateTT, direction, synodicMonthDays)
+	return basic.CalcMoonSHByJDE(candidateTT+float64(direction*step)*synodicMonthDays, phaseType)
+}
+
+func eclipseSearchStep(candidateTT float64, direction int, synodicMonthDays float64) int {
+	step := 1
+	for nextStep := 2; nextStep <= eclipseSeasonMaxSearchStep; nextStep++ {
+		skippedTT := candidateTT + float64(direction*(nextStep-1))*synodicMonthDays
+		if eclipseNodeDistance(skippedTT) < eclipseSeasonNodeDistanceLimitDeg {
+			break
+		}
+		step = nextStep
+	}
+	return step
+}
+
+func eclipseNodeDistance(ttJDE float64) float64 {
+	argument := normalizeDegree360(basic.MoonLonX(ttJDE))
+	toAscending := math.Min(argument, 360-argument)
+	toDescending := math.Abs(argument - 180)
+	return math.Min(toAscending, toDescending)
+}