feat(ScheduleView): enhance player selection logic and eligibility checks

- Introduced new methods to determine the lineup half for matches and fetch eligible member IDs based on the selected team.
- Improved player selection dialog to filter visible members based on active status and eligibility, ensuring a more accurate representation of available players.
- Added logic to handle preselected player IDs, enhancing the user experience during team selection.

frontend/src/views/ScheduleView.vue

@@ -640,15 +640,25 @@ export default {
                 const readyIds = normalizePlayersList(match.playersReady);
                 const plannedIds = normalizePlayersList(match.playersPlanned);
                 const playedIds = normalizePlayersList(match.playersPlayed);
+                const preselectedIds = Array.from(new Set([...readyIds, ...plannedIds, ...playedIds]));
 
                 // Fetch members for the current club
                 const response = await apiClient.get(`/clubmembers/get/${this.currentClub}/true`);
-                
                 const allMembers = response.data;
-                
-                const activeMembers = allMembers.filter(m => m.active);
-                
-                this.playerSelectionDialog.members = activeMembers.map(m => ({
+
+                const lineupHalf = this.getLineupHalfForMatch(match);
+                const eligibleMemberIds = await this.getEligibleMemberIdsForSelectedTeam(lineupHalf);
+                const activeMembers = allMembers.filter(member => member.active);
+                const allowedIds = new Set(
+                    [...eligibleMemberIds, ...preselectedIds]
+                        .map((id) => Number(id))
+                        .filter((id) => Number.isFinite(id))
+                );
+                const visibleMembers = allowedIds.size > 0
+                    ? activeMembers.filter((member) => allowedIds.has(Number(member.id)))
+                    : activeMembers;
+
+                this.playerSelectionDialog.members = visibleMembers.map(m => ({
                     ...m,
                     isReady: readyIds.includes(m.id) || false,
                     isPlanned: plannedIds.includes(m.id) || false,
@@ -663,6 +673,46 @@ export default {
                 this.playerSelectionDialog.loading = false;
             }
         },
+        getLineupHalfForMatch(match) {
+            const matchDate = new Date(match?.date);
+            if (Number.isNaN(matchDate.getTime())) {
+                return 'first_half';
+            }
+            // Rueckrunde: Januar bis Juni
+            return matchDate.getMonth() <= 5 ? 'second_half' : 'first_half';
+        },
+        async getEligibleMemberIdsForSelectedTeam(lineupHalf) {
+            if (!this.selectedTeam?.id) {
+                return [];
+            }
+
+            const selectedIndex = this.teams.findIndex(team => Number(team.id) === Number(this.selectedTeam.id));
+            if (selectedIndex < 0) {
+                return [];
+            }
+
+            // Niedrigere Mannschaften = ausgewaehltes Team + alle dahinter in der sortierten Teamliste
+            const candidateTeams = this.teams.slice(selectedIndex);
+            const lineupResponses = await Promise.all(candidateTeams.map(async (team) => {
+                try {
+                    const response = await apiClient.get(`/club-teams/${team.id}/lineup`, {
+                        params: { half: lineupHalf }
+                    });
+                    return Array.isArray(response.data) ? response.data : [];
+                } catch (error) {
+                    return [];
+                }
+            }));
+
+            const ids = new Set();
+            lineupResponses.flat().forEach((assignment) => {
+                const memberId = Number(assignment?.memberId);
+                if (Number.isFinite(memberId)) {
+                    ids.add(memberId);
+                }
+            });
+            return Array.from(ids);
+        },
         
         closePlayerSelectionDialog() {
             this.playerSelectionDialog.isOpen = false;