Provide metadata in transform; add attributes there

Provide metadata in transform; add attributes there

The metadata actually depends on the parser, so it’s a recursive
dependency to make the parser use it. Instead, just make it available
in transforms and add the various ⛩️📰 书社 attributes during the
expansion phase.

Literally including the metadata R·D·F in the transform greatly
increases its file size, but it “should” be fine.

This commit also brings with it a few other improvements and changes to
transforms :⁠—

- All of the `$书社:*` variables which used to return result tree
    fragments now return node sets.

- The `书社:application` mode has been renamed to `书社:apply`, to
    match `书社:expand`.