fix: weaken re-keyed child refs in rename to prevent mock leak

lib/Test/MockFile.pm

@@ -4101,6 +4101,7 @@ sub __rename ($$) {
 
             delete $files_being_mocked{$key};
             $files_being_mocked{$new_key} = $child;
+            Scalar::Util::weaken( $files_being_mocked{$new_key} );
             $child->{'path'} = $new_key;
 
             # Update autovivify tracking for child directories

t/rename.t

@@ -8,6 +8,7 @@ use Test2::Tools::Explain;
 use Test2::Plugin::NoWarnings;
 
 use Errno qw/ENOENT EISDIR ENOTDIR ENOTEMPTY/;
+use Scalar::Util qw/isweak/;
 
 use Test::MockFile qw< nostrict >;
 
@@ -227,6 +228,23 @@ note "-------------- rename: directory DESTROY cleanup works after rename ------
     ok( -e '/mock/dtor2/f.txt', 'child accessible before DESTROY' );
 }
 
+note "-------------- rename: re-keyed children keep weak refs in files_being_mocked --------------";
+{
+    my $dir   = Test::MockFile->new_dir('/mock/weaktest');
+    my $child = Test::MockFile->file( '/mock/weaktest/w.txt', 'data' );
+    my $dest  = Test::MockFile->dir('/mock/weaktest2');
+
+    ok( rename( '/mock/weaktest', '/mock/weaktest2' ), 'rename for weakref test' );
+
+    ok( isweak( $Test::MockFile::files_being_mocked{'/mock/weaktest2/w.txt'} ),
+        'child entry in files_being_mocked is weakened after directory rename' );
+
+    # When user drops the reference, mock should be garbage collected
+    undef $child;
+    ok( !defined $Test::MockFile::files_being_mocked{'/mock/weaktest2/w.txt'},
+        'child mock is garbage collected after user drops reference' );
+}
+
 note "-------------- rename: preserves inode and nlink --------------";
 {
     my $old = Test::MockFile->file( '/mock/ino_old', 'data', { inode => 42, nlink => 3 } );