`Page::copy` gives a page's content fresh identities (every `{guid},n` in the model, keys
and references alike, becomes `{fresh},1`) with its definitions and payloads, and
`Section::import_page` queues a page creation and a save for it in the destination, so a
copy publishes offline like any edit; `Section::delete_pages` completes a move. Picture
and attachment payloads now serialize with the model (base64), because a queued intent
replayed without them failed publication for any new picture or attachment.

The writer learned what copied pages need: a new outline may start with a picture, table,
attachment or ink paragraph and takes the model's indentation table; a new paragraph in a
new outline may reference a paragraph style, whose object the writer creates from the
definition as OneNote keeps quick styles. A styled paragraph appended to a stored outline
still stays for review, as the split-merge lane expects.

`corpus/page-copy` is the cold read of eight copied pages (text with attachment, table,
picture, ink, tags, lists, equations, paragraph formatting) with screenshots; the
`QuickStyleDef` export carries the copied style's font, size and colour.
`evidence/P01-BASELINE.md` records the queue and large-notebook baselines.

Assisted-by: claude-fable-5.1