Adapts an envelope-returning builtin to the legacy printing handler shape.
This is the compatibility bridge for incremental conversion: converted
builtins return envelopes, and this wrapper delivers them through the
active sink so the dispatch table, pipes and redirects need no changes.
A handler that resolves without an envelope (as stubbed handlers in tests
do) is treated as having produced no output.
Adapts an envelope-returning builtin to the legacy printing handler shape.
This is the compatibility bridge for incremental conversion: converted builtins return envelopes, and this wrapper delivers them through the active sink so the dispatch table, pipes and redirects need no changes. A handler that resolves without an envelope (as stubbed handlers in tests do) is treated as having produced no output.