Per-section resolve. An offloaded block stays behind one <<swload:...>> marker with a covering table, but resolve now takes an optional selector so the agent fetches just one slice instead of pulling the whole block: a `/`-path of `field=value`, `[n]`, or field-name segments, or `L<a>-<b>` for a line range (e.g. `number=13932/body`). A string field returns verbatim; resolving the marker with no selector still returns the exact original bytes.