feat(mannschaften): align public pages with season query logic

components/MannschaftenUebersicht.vue

@@ -52,7 +52,7 @@
           <!-- Mannschaftsaufstellung -->
           <div class="border-t border-gray-200 pt-6">
             <h3 class="text-xl font-semibold text-gray-900 mb-4">
-              Mannschaftsaufstellung Saison 2025/26
+              Mannschaftsaufstellung Saison {{ selectedSeasonLabel }}
             </h3>
             <div class="grid sm:grid-cols-2 lg:grid-cols-4 gap-4">
               <div
@@ -102,11 +102,36 @@
 </template>
 
 <script setup>
-import { ref, onMounted } from 'vue'
+import { ref, onMounted, computed } from 'vue'
 import { Users } from 'lucide-vue-next'
 
+const props = defineProps({
+  season: {
+    type: String,
+    default: ''
+  }
+})
+
 const mannschaften = ref([])
 
+const getCurrentSeasonSlug = () => {
+  const now = new Date()
+  const year = now.getFullYear()
+  const startYear = now.getMonth() >= 6 ? year : year - 1
+  const endYear = startYear + 1
+  return `${String(startYear).slice(-2)}--${String(endYear).slice(-2)}`
+}
+
+const selectedSeason = computed(() => {
+  const value = String(props.season || '').trim()
+  return /^\d{2}--\d{2}$/.test(value) ? value : getCurrentSeasonSlug()
+})
+
+const selectedSeasonLabel = computed(() => {
+  const match = String(selectedSeason.value || '').match(/^(\d{2})--(\d{2})$/)
+  return match ? `20${match[1]}/${match[2]}` : selectedSeason.value
+})
+
 async function fetchCsvText(url) {
   const attempt = async () => {
     const withBuster = `${url}${url.includes('?') ? '&' : '?'}_t=${Date.now()}`
@@ -125,7 +150,9 @@ async function fetchCsvText(url) {
 
 const loadMannschaften = async () => {
   try {
-    const csv = await fetchCsvText('/api/mannschaften')
+    const params = new URLSearchParams()
+    if (selectedSeason.value) params.set('season', selectedSeason.value)
+    const csv = await fetchCsvText(`/api/mannschaften${params.toString() ? `?${params.toString()}` : ''}`)
     
     // Vereinfachter CSV-Parser
     const lines = csv.split('\n').filter(line => line.trim() !== '')