OneNote's compaction zeroes the manifest-list references of deleted object
spaces and unused file-data references in place (fcrZero). Those now read as
freed: their spaces are absent, their payloads are not declared, and appends
keep the free chunk list. Sections compacted by OneNote on Windows open again.
Also: the model oracle passes a paragraph's style to equation spans, and the
structural-probe fixtures move into corpus/ so a clean clone builds its tests.

Assisted-by: claude-opus-5.5