resolve-open-questionslisted

Resolve a design doc's Open Questions by asking the user directly, then fold their answers back into the doc. $ARGUMENTS is the path to an HLD or LLD file. The path may be omitted if it's already clear from this conversation — see step 1. Steps: 1. Determine the target path: - If $ARGUMENTS contains a path, use it. - If not, look back through this conversation for an HLD or LLD path already established (created via `/hld`/`/lld`, or referenced by an earlier `/spike`, `/add-spike`, `/resolve-open-questions`, `/implement-lld`, or `/reconcile` call in this session). If exactly one is found, confirm it with the user before proceeding rather than silently assuming. If more than one is found, list them and ask which to use. If none is found, ask the user to provide a path and stop. - Check that the file at that path exists. If it does not, tell the user and stop. 1. Read the file's `## Open Questions` section and collect every unchecked (`- [ ]`) question. If none remain, tell the user there's nothing to resolve and stop. 1. For each unresolved question, ask the user directly — never answer it yourself or assume a default. Formulate 2-4 concrete answer options grounded in the rest of the doc's actual content (never generic placeholders), with a recommended option first when there's a clear default; the user can always answer outside the given options. Batch up to a handful of questions per round if there are several, running additional rounds for any that remain. Wait