fix(context-config): clean up visibility/allowlist on unregister and fix migration schemas

- Add context_visibility and context_allowlists cleanup to both
  unregister_context_from_group and proxy_unregister_from_group to
  prevent storage leaks and stale data on re-registration
- Remove nonexistent context_count field from OldOnChainGroupMeta in
  migrations 04-06 to match the actual on-chain schema and prevent
  borsh deserialization corruption

Co-Authored-By: Claude Opus 4.6 <[email protected]>

Author: rtb-12

contracts/near/context-config/src/mutate.rs

@@ -872,7 +872,9 @@ impl ContextConfigs {
             .collect();
         for signer in &all_signers {
             let _ignored = group.member_contexts.remove(&(signer.clone(), *context_id));
+            let _ignored = group.context_allowlists.remove(&(*context_id, signer.clone()));
         }
+        let _ignored = group.context_visibility.remove(&context_id);
 
         let _ignored = self.context_group_refs.remove(&context_id);
 
@@ -1309,7 +1311,9 @@ impl ContextConfigs {
             .collect();
         for signer in &all_signers {
             let _ignored = group.member_contexts.remove(&(signer.clone(), *context_id));
+            let _ignored = group.context_allowlists.remove(&(*context_id, signer.clone()));
         }
+        let _ignored = group.context_visibility.remove(&context_id);
 
         let _ignored = self.context_group_refs.remove(&context_id);
 

contracts/near/context-config/src/sys/migrations/04_group_invitations.rs

@@ -48,7 +48,6 @@ struct OldOnChainGroupMeta {
     pub members: IterableSet<SignerId>,
     pub approved_registrations: IterableSet<ContextId>,
     pub context_ids: IterableSet<ContextId>,
-    pub context_count: u64,
 }
 
 pub fn migrate() {

contracts/near/context-config/src/sys/migrations/05_group_migration_method.rs

@@ -48,7 +48,6 @@ struct OldOnChainGroupMeta {
     pub members: IterableSet<SignerId>,
     pub approved_registrations: IterableSet<ContextId>,
     pub context_ids: IterableSet<ContextId>,
-    pub context_count: u64,
     pub invitation_commitments: IterableMap<CryptoHash, BlockHeight>,
     pub used_invitations: IterableSet<CryptoHash>,
     pub member_contexts: IterableMap<(SignerId, ContextId), ContextIdentity>,

contracts/near/context-config/src/sys/migrations/06_group_permissions.rs

@@ -49,7 +49,6 @@ struct OldOnChainGroupMeta {
     pub members: IterableSet<SignerId>,
     pub approved_registrations: IterableSet<ContextId>,
     pub context_ids: IterableSet<ContextId>,
-    pub context_count: u64,
     pub invitation_commitments: IterableMap<CryptoHash, BlockHeight>,
     pub used_invitations: IterableSet<CryptoHash>,
     pub member_contexts: IterableMap<(SignerId, ContextId), ContextIdentity>,