The add_file_context function used a positional zip() to pair API
payload messages with DB-stored messages. After
process_messages_with_output() expands assistant messages containing
tool calls into multiple OpenAI-format messages (assistant + tool
results), the payload list becomes longer than the stored list. This
caused the zip to misalign, so subsequent user messages never received
their attached_files tags -- the model could see uploaded images via
vision but had no file URL to pass to edit_image.
Fix: filter both lists to user-role messages only before zipping.
User messages maintain the same order in both lists regardless of
assistant message expansion, restoring correct file context injection.
Fixes#21878
Classic298
bfc606a9e3