feat: 完善日月食与月掩几何链路并扩展历法接口

- 新增日月食中心带、偏食带、阴影足迹、等时线、食分线及升落边界计算，支持极区与混合食拓扑
- 新增日食单时刻阴影求解器、站心状态查询、批量采样和 ΔT 覆盖接口
- 重构恒星与行星月掩路径，补充有限盘面接触、站心修正、掩带宽度、极区投影及升落边界
- 扩展 SVG 与 GeoJSON 输出，支持详细面板、全球/极区/地球投影、边界闭合、时间标记和拓扑签名
- 扩展日月食候选搜索、局地搜索、沙罗序列预计算与范围外推，补充系列锚点和成员一致性校验
- 补齐古历纪年、儒略历独有闰日、多公历候选、历法改革跨日及精确日期运算接口
- 优化 ΔT、章动、恒星时、月球地平线、事件根搜索和本地星历缓存，降低重复计算开销并提升边界稳定

jupiter/phenomena_contact_events_test.go

@@ -94,3 +94,69 @@ func assertGalileanContactMatchesBasic(
 		t.Fatalf("%s phase mismatch: got %q want %q", name, got.Phase, want.Phase)
 	}
 }
+
+// IMCCE 年表每个事件给 4 个时刻：D1、D2 = D1+时长、F1、F2 = F1+时长。
+func TestGalileanPhenomenonContactEventMatchesIMCCEBaseline(t *testing.T) {
+	records := loadGalileanPublicEventBaseline(t)
+	const (
+		contactTolerance  = 120 * time.Second
+		durationTolerance = 25 * time.Second
+	)
+	var maxContact, maxDuration time.Duration
+	for _, record := range records {
+		startUTC := mustParseGalileanEventTime(t, record.StartUTC)
+		endUTC := mustParseGalileanEventTime(t, record.EndUTC)
+		startDuration := time.Duration(record.StartDurationMinutes * float64(time.Minute))
+		endDuration := time.Duration(record.EndDurationMinutes * float64(time.Minute))
+		endOfEvent := endUTC.Add(endDuration)
+		midpoint := startUTC.Add(endOfEvent.Sub(startUTC) / 2)
+
+		got := ClosestGalileanPhenomenonContactEvent(midpoint, record.Satellite, GalileanPhenomenonType(record.Type))
+		if !got.Valid {
+			t.Fatalf("%s returned no contact event", record.Label)
+		}
+		contacts := []struct {
+			name string
+			got  time.Time
+			want time.Time
+		}{
+			{"D1", got.Disappearance.Start, startUTC},
+			{"D2", got.Disappearance.End, startUTC.Add(startDuration)},
+			{"F1", got.Reappearance.Start, endUTC},
+			{"F2", got.Reappearance.End, endOfEvent},
+		}
+		for _, contact := range contacts {
+			delta := contact.got.Sub(contact.want)
+			if delta < 0 {
+				delta = -delta
+			}
+			if delta > maxContact {
+				maxContact = delta
+			}
+			if delta > contactTolerance {
+				t.Fatalf("%s %s offset %v exceeds %v", record.Label, contact.name, contact.got.Sub(contact.want), contactTolerance)
+			}
+		}
+		durations := []struct {
+			name string
+			got  time.Duration
+			want time.Duration
+		}{
+			{"D", got.Disappearance.Duration, startDuration},
+			{"F", got.Reappearance.Duration, endDuration},
+		}
+		for _, duration := range durations {
+			delta := duration.got - duration.want
+			if delta < 0 {
+				delta = -delta
+			}
+			if delta > maxDuration {
+				maxDuration = delta
+			}
+			if delta > durationTolerance {
+				t.Fatalf("%s %s-phase duration offset %v exceeds %v", record.Label, duration.name, duration.got-duration.want, durationTolerance)
+			}
+		}
+	}
+	t.Logf("contact offset max %v, duration offset max %v", maxContact, maxDuration)
+}