feat: Geschwindigkeits-Farbverlauf auf der Track-Karte und stabiler Leaflet-Lifecycle.

Verzögertes fitBounds, Error Boundary und sauberes Map-Cleanup beheben den Absturz, der die Logbuch-Ansicht leer ließ.

Co-authored-by: Cursor <cursoragent@cursor.com>

client/src/utils/trackMapColors.ts

@@ -0,0 +1,75 @@
+import type { TrackWaypoint } from '../services/trackUpload.js'
+
+const NM_IN_METERS = 1852
+const MAX_PLAUSIBLE_KNOTS = 50
+const FALLBACK_GREEN = '#16a34a'
+
+function haversineMeters(lat1: number, lon1: number, lat2: number, lon2: number): number {
+  const R = 6371000
+  const p1 = (lat1 * Math.PI) / 180
+  const p2 = (lat2 * Math.PI) / 180
+  const dLat = ((lat2 - lat1) * Math.PI) / 180
+  const dLon = ((lon2 - lon1) * Math.PI) / 180
+  const a =
+    Math.sin(dLat / 2) ** 2 +
+    Math.cos(p1) * Math.cos(p2) * Math.sin(dLon / 2) ** 2
+  return 2 * R * Math.asin(Math.sqrt(a))
+}
+
+function hasMeaningfulTimestamps(waypoints: TrackWaypoint[]): boolean {
+  if (waypoints.length < 2) return false
+  const first = waypoints[0].timestamp
+  const last = waypoints[waypoints.length - 1].timestamp
+  return last > first + 60_000
+}
+
+export function getSegmentSpeedsKn(waypoints: TrackWaypoint[]): number[] {
+  if (waypoints.length < 2) return []
+
+  const timed = hasMeaningfulTimestamps(waypoints)
+  const speeds: number[] = []
+
+  for (let i = 1; i < waypoints.length; i++) {
+    const prev = waypoints[i - 1]
+    const curr = waypoints[i]
+    let speedKn = 0
+
+    const tagged = [prev.speedKnots, curr.speedKnots].filter(
+      (value): value is number => value != null && value > 0
+    )
+    if (tagged.length > 0) {
+      speedKn = tagged.reduce((sum, value) => sum + value, 0) / tagged.length
+    } else if (timed) {
+      const dtMs = curr.timestamp - prev.timestamp
+      const segmentM = haversineMeters(prev.lat, prev.lng, curr.lat, curr.lng)
+      if (dtMs > 0 && segmentM > 0) {
+        speedKn = (segmentM / NM_IN_METERS) / (dtMs / 3_600_000)
+      }
+    }
+
+    if (speedKn > MAX_PLAUSIBLE_KNOTS) speedKn = 0
+    speeds.push(speedKn)
+  }
+
+  return speeds
+}
+
+export function hasSpeedGradientData(speeds: number[]): boolean {
+  const valid = speeds.filter((speed) => speed > 0)
+  if (valid.length < 2) return false
+  const min = Math.min(...valid)
+  const max = Math.max(...valid)
+  return max - min >= 0.3
+}
+
+/** Green (slow) → yellow → red (fast) */
+export function speedToTrackColor(speedKn: number, minKn: number, maxKn: number): string {
+  if (speedKn <= 0 || maxKn <= minKn) return FALLBACK_GREEN
+  const t = Math.max(0, Math.min(1, (speedKn - minKn) / (maxKn - minKn)))
+  const hue = 120 - t * 120
+  return `hsl(${hue}, 72%, 42%)`
+}
+
+export function getTrackLineColor(speeds: number[]): string {
+  return hasSpeedGradientData(speeds) ? '' : FALLBACK_GREEN
+}