fix: Add display_in_workshop to groupFormatter and fix filter logic

Problem: Moderation filter returned 0 groups because:
1. groupFormatter.formatGroupDetail() didn't include display_in_workshop field
2. Platform filters incorrectly required workshop consent

Solution:
- Add display_in_workshop and consent_timestamp to formatGroupDetail()
- Remove workshop requirement from platform filters
- Add default filter to show only groups with workshop consent
- Fix workshop-only filter to check for consented social media

Filter logic:
- 'Alle Gruppen': Only groups WITH workshop consent
- 'Nur Werkstatt': Groups with workshop BUT WITHOUT social media
- Platform filters: Groups with that platform consent (independent of workshop)

backend/src/routes/groups.js

@@ -49,23 +49,32 @@ router.get('/moderation/groups', async (req, res) => {
             })
         );
         
-        // Jetzt filtern wir basierend auf den Query-Parametern
+                // Jetzt filtern wir basierend auf den Query-Parametern
         let filteredGroups = groupsWithConsents;
         
         if (workshopOnly === 'true') {
-            // Filter: Nur Gruppen mit Werkstatt-Consent aber OHNE Social Media Consents
+            // Filter: Nur Gruppen MIT Werkstatt-Consent aber OHNE zugestimmte Social Media Consents
-            filteredGroups = groupsWithConsents.filter(group => 
+            filteredGroups = groupsWithConsents.filter(group => {
-                group.display_in_workshop && 
+                // Muss Werkstatt-Consent haben
-                (!group.socialMediaConsents || group.socialMediaConsents.length === 0)
+                if (!group.display_in_workshop) return false;
-            );
+                
+                // Darf KEINE zugestimmten Social Media Consents haben
+                const hasConsentedSocialMedia = group.socialMediaConsents && 
+                    group.socialMediaConsents.some(consent => consent.consented === 1 || consent.consented === true);
+                
+                return !hasConsentedSocialMedia;
+            });
         } else if (platform) {
-            // Filter: Gruppen mit bestimmter Social Media Platform
+            // Filter: Gruppen mit bestimmter Social Media Platform (unabhängig vom Werkstatt-Consent)
             filteredGroups = groupsWithConsents.filter(group => 
                 group.socialMediaConsents && 
                 group.socialMediaConsents.some(consent => 
-                    consent.platform_name === platform && consent.consented
+                    consent.platform_name === platform && (consent.consented === 1 || consent.consented === true)
                 )
             );
+        } else {
+            // Kein Filter: Zeige nur Gruppen MIT Werkstatt-Consent (das ist die Mindestanforderung)
+            filteredGroups = groupsWithConsents.filter(group => group.display_in_workshop);
         }
         
         res.json({

backend/src/utils/groupFormatter.js

@@ -24,6 +24,8 @@ function formatGroupDetail(groupRow, images) {
         name: groupRow.name,
         uploadDate: groupRow.upload_date,
         approved: Boolean(groupRow.approved),
+        display_in_workshop: Boolean(groupRow.display_in_workshop),
+        consent_timestamp: groupRow.consent_timestamp || null,
         images: images.map(img => ({
             id: img.id,
             fileName: img.file_name,