feat: Trail-Stores registrieren und Navigationseintrag ergänzen

Die vier Trail-Stores (trails, trailVersions, trailFlags, trailMarkers)
werden im Dashboard-Layout per Context bereitgestellt, laden ihre Daten
beim Mount, abonnieren Realtime-Updates und werden beim Unmount wieder
aufgeräumt. Zusätzlich ergänzt ein Navigationseintrag „Trails" mit dem
Route-Icon aus lucide-svelte.

frontend/src/routes/dashboard/+layout.svelte

@@ -7,11 +7,15 @@
     import { setRunContext } from '$lib/stores/runs.svelte'
     import { setRiderContext } from '$lib/stores/riders.svelte'
     import { setTimeContext } from '$lib/stores/times.svelte'
+    import { setTrailContext } from '$lib/stores/trails.svelte'
+    import { setTrailVersionContext } from '$lib/stores/trailVersions.svelte'
+    import { setTrailFlagContext } from '$lib/stores/trailFlags.svelte'
+    import { setTrailMarkerContext } from '$lib/stores/trailMarkers.svelte'
     import { Button } from '@/components/ui/button'
     import { Separator } from '@/components/ui/separator'
     import Logo from '$lib/components/Logo.svelte'
     import TeamSwitcher from '$lib/components/TeamSwitcher.svelte'
-    import { Home, Calendar, Flag, Timer, LogOut, Menu, X, Moon, Sun } from 'lucide-svelte'
+    import { Home, Calendar, Flag, Timer, LogOut, Menu, X, Moon, Sun, Route } from 'lucide-svelte'
     import { toggleMode, mode } from 'mode-watcher'
     import { onDestroy, onMount } from 'svelte'
 
@@ -24,6 +28,10 @@
     const runs = setRunContext()
     const riders = setRiderContext()
     const times = setTimeContext()
+    const trails = setTrailContext()
+    const trailVersions = setTrailVersionContext()
+    const trailFlags = setTrailFlagContext()
+    const trailMarkers = setTrailMarkerContext()
 
     let isMobileMenuOpen = $state(false)
 
@@ -35,11 +43,18 @@
         // Teams zuerst laden, weil die anderen Stores nach team filtern
         await teams.load()
         teams.subscribe()
-        await Promise.all([events.load(), runs.load(), riders.load(), times.load()])
+        await Promise.all([
+            events.load(), runs.load(), riders.load(), times.load(),
+            trails.load(), trailVersions.load(), trailFlags.load(), trailMarkers.load(),
+        ])
         events.subscribe()
         runs.subscribe()
         riders.subscribe()
         times.subscribe()
+        trails.subscribe()
+        trailVersions.subscribe()
+        trailFlags.subscribe()
+        trailMarkers.subscribe()
     })
 
     onDestroy(() => {
@@ -48,6 +63,10 @@
         runs.destroy()
         riders.destroy()
         times.destroy()
+        trails.destroy()
+        trailVersions.destroy()
+        trailFlags.destroy()
+        trailMarkers.destroy()
     })
 
     function handleLogout() {
@@ -66,6 +85,7 @@
     const nav = [
         { href: '/dashboard', icon: Home, label: 'Dashboard' },
         { href: '/dashboard/events', icon: Calendar, label: 'Events' },
+        { href: '/dashboard/trails', icon: Route, label: 'Trails' },
         { href: '/dashboard/timing', icon: Timer, label: 'Zeitnahme' },
         { href: '/dashboard/results', icon: Flag, label: 'Ergebnisse' },
     ]