Kalender-Warnschwelle konfigurierbar + Saison-Datepicker

- kalender_warnung_prozent Setting: Admin kann Grün→Orange-Schwelle einstellen
- Verfügbarkeits-API liefert Warnschwelle mit, BookingCalendar nutzt dynamischen Wert
- Saison-Start/Ende als Date-Picker statt Textfeld im Admin-Dashboard

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/app/admin/dashboard/page.tsx

@@ -564,14 +564,16 @@ export default function AdminDashboardPage() {
           <div className="space-y-5 max-w-xl">
             <h3 className="text-lg font-bold text-primary">Einstellungen</h3>
             <div className="bg-white rounded-2xl border border-border divide-y divide-border/50">
-              {settings.map((s) => (
+              {settings.map((s) => {
+                const isDate = s.key === 'saison_start' || s.key === 'saison_ende';
+                return (
                   <div key={s.key} className="p-4 flex items-center gap-4">
                     <div className="flex-1">
                       <div className="font-medium text-sm">{s.beschreibung || s.key}</div>
                       <div className="text-[11px] text-text-muted font-mono">{s.key}</div>
                     </div>
                     <input
-                    type="text"
+                      type={isDate ? 'date' : 'text'}
                       defaultValue={s.value}
                       onBlur={(e) => {
                         if (e.target.value !== s.value) {
@@ -582,7 +584,8 @@ export default function AdminDashboardPage() {
                       aria-label={s.beschreibung || s.key}
                     />
                   </div>
-              ))}
+                );
+              })}
             </div>
             <p className="text-xs text-text-muted">
               Änderungen werden beim Verlassen des Feldes gespeichert.

src/app/api/pool/verfuegbarkeit/route.ts

@@ -37,18 +37,24 @@ export async function GET(request: NextRequest) {
       summe_m3: info.summe_m3,
     }));
 
-    // Max m³ pro Tag laden
-    const { data: setting } = await supabase
+    // Settings laden (max_m3_per_day + kalender_warnung_prozent)
+    const { data: settingsData } = await supabase
       .from('settings')
-      .select('value')
-      .eq('key', 'max_m3_per_day')
-      .single();
+      .select('key, value')
+      .in('key', ['max_m3_per_day', 'kalender_warnung_prozent']);
 
-    const maxM3PerDay = setting ? parseInt(setting.value) : 150;
+    const settingsMap: Record<string, string> = {};
+    settingsData?.forEach((s: { key: string; value: string }) => {
+      settingsMap[s.key] = s.value;
+    });
+
+    const maxM3PerDay = settingsMap['max_m3_per_day'] ? parseInt(settingsMap['max_m3_per_day']) : 150;
+    const kalenderWarnungProzent = settingsMap['kalender_warnung_prozent'] ? parseInt(settingsMap['kalender_warnung_prozent']) : 30;
 
     return NextResponse.json({
       verfuegbarkeit,
       max_m3_per_day: maxM3PerDay,
+      kalender_warnung_prozent: kalenderWarnungProzent,
     });
   } catch (err) {
     console.error('Verfügbarkeit Error:', err);

src/components/BookingCalendar.tsx

@@ -37,6 +37,7 @@ export default function BookingCalendar({ onDateSelect, selectedDate, requestedM
   const [viewYear] = useState(currentYear);
   const [auslastungM3, setAuslastungM3] = useState<Record<string, number>>({});
   const [maxM3PerDay, setMaxM3PerDay] = useState(150);
+  const [warnungProzent, setWarnungProzent] = useState(30);
   const [loading, setLoading] = useState(true);
 
   const isBrunnen = wasserquelle === 'brunnen';
@@ -55,6 +56,9 @@ export default function BookingCalendar({ onDateSelect, selectedDate, requestedM
       if (data.max_m3_per_day) {
         setMaxM3PerDay(data.max_m3_per_day);
       }
+      if (data.kalender_warnung_prozent != null) {
+        setWarnungProzent(data.kalender_warnung_prozent);
+      }
     } catch {
       // silent
     } finally {
@@ -97,7 +101,7 @@ export default function BookingCalendar({ onDateSelect, selectedDate, requestedM
     const freeM3 = maxM3PerDay - usedM3;
 
     if (requestedM3 && freeM3 < requestedM3) return 'full';
-    if (freeM3 <= maxM3PerDay * 0.3) return 'partial';
+    if (freeM3 <= maxM3PerDay * (warnungProzent / 100)) return 'partial';
     return 'available';
   }