Refactor saveMember function to improve duplicate member handling and streamline member updates. Enhance error messaging for non-existent members and ensure new members are added with default active status.

server/utils/members.js

@@ -242,24 +242,28 @@ export async function saveMember(memberData) {
   const members = await readMembers()
   
   if (memberData.id) {
-    // Update existing
+    // Update existing manual member if present.
+    // If the ID belongs to a login-only member shown in the merged list,
+    // create a manual overlay with the same ID so editable fields can be stored.
     const index = members.findIndex(m => m.id === memberData.id)
+    const duplicate = findDuplicateMember(
+      members.filter(m => m.id !== memberData.id),
+      memberData.firstName,
+      memberData.lastName,
+      memberData.geburtsdatum
+    )
+
+    if (duplicate) {
+      throw new Error('Ein Mitglied mit diesem Namen und Geburtsdatum existiert bereits.')
+    }
+
     if (index !== -1) {
-      // Check for duplicate (excluding current member)
-      const duplicate = findDuplicateMember(
-        members.filter(m => m.id !== memberData.id),
-        memberData.firstName,
-        memberData.lastName,
-        memberData.geburtsdatum
-      )
-      
-      if (duplicate) {
-        throw new Error('Ein Mitglied mit diesem Namen und Geburtsdatum existiert bereits.')
-      }
-      
       members[index] = { ...members[index], ...memberData }
     } else {
-      throw new Error('Mitglied nicht gefunden')
+      members.push({
+        ...memberData,
+        active: typeof memberData.active === 'boolean' ? memberData.active : true
+      })
     }
   } else {
     // Add new - check for duplicate first