fix: resolve invite overflow and member removal lookup

lib/screens/manage_collection_screen.dart

@@ -146,7 +146,10 @@ class _ManageCollectionScreenState extends State<ManageCollectionScreen> {
           child: const Icon(Icons.person_add, color: Colors.white, size: 28),
         ),
         title: const Text('Invite Member'),
-        content: Column(
+        content: SingleChildScrollView(
+          child: ConstrainedBox(
+            constraints: const BoxConstraints(maxWidth: 420),
+            child: Column(
               mainAxisSize: MainAxisSize.min,
               children: [
                 const Text(
@@ -186,6 +189,8 @@ class _ManageCollectionScreenState extends State<ManageCollectionScreen> {
                 ),
               ],
             ),
+          ),
+        ),
         actions: [
           TextButton(
             onPressed: () => Navigator.pop(context),
@@ -256,7 +261,7 @@ class _ManageCollectionScreenState extends State<ManageCollectionScreen> {
     try {
       await CollectionService.removeMember(
         collectionId: _collection.id,
-        membershipId: member.id,
+        memberUserId: member.userId,
       );
       showGlobalSnackBar('Member removed.');
       await _loadMembers();

lib/services/collection_service.dart

@@ -326,7 +326,7 @@ class CollectionService {
   /// Remove a member from a collection.
   static Future<void> removeMember({
     required String collectionId,
-    required String membershipId,
+    required String memberUserId,
   }) async {
     final currentUserId = supabase.auth.currentUser!.id;
 
@@ -346,7 +346,7 @@ class CollectionService {
     final target = await supabase
         .from('collection_members')
         .select('role, user_id')
-        .eq('id', membershipId)
+      .eq('user_id', memberUserId)
         .eq('collection_id', collectionId)
         .maybeSingle();
 
@@ -360,7 +360,8 @@ class CollectionService {
     await supabase
         .from('collection_members')
         .delete()
-        .eq('id', membershipId);
+      .eq('user_id', memberUserId)
+      .eq('collection_id', collectionId);
   }
 
   /// Leave a collection (for non-owners).