Fix conflicts with other extension visibility scoping (#26)

Wrapping all `wheres` in an `orWhere` ensures that there's no conflict.

See https://github.com/flarum/core/issues/2798, https://github.com/flarum/docs/pull/200

extensions/approval/src/Access/ScopePrivateDiscussionVisibility.php

@@ -20,6 +20,10 @@ class ScopePrivateDiscussionVisibility
      */
     public function __invoke(User $actor, Builder $query)
     {
+        // All statements need to be wrapped in an orWhere, since we're adding a
+        // subset of private discussions that should be visible, not restricting the visible
+        // set.
+        $query->orWhere(function ($query) use ($actor) {
             // Show empty/private discussions if they require approval and they are
             // authored by the current user, or the current user has permission to
             // approve posts.
@@ -33,5 +37,6 @@ class ScopePrivateDiscussionVisibility
                         });
                 });
             }
+        });
     }
 }

extensions/approval/src/Access/ScopePrivatePostVisibility.php

@@ -21,6 +21,10 @@ class ScopePrivatePostVisibility
      */
     public function __invoke(User $actor, Builder $query)
     {
+        // All statements need to be wrapped in an orWhere, since we're adding a
+        // subset of private posts that should be visible, not restricting the visible
+        // set.
+        $query->orWhere(function ($query) use ($actor) {
             // Show private posts if they require approval and they are
             // authored by the current user, or the current user has permission to
             // approve posts.
@@ -32,6 +36,7 @@ class ScopePrivatePostVisibility
                         ->orWhereExists($this->discussionWhereCanApprovePosts($actor));
                 });
             }
+        });
     }
 
     private function discussionWhereCanApprovePosts(User $actor)