Assemble revision manifests for multiple spaces behind one transaction-count update while retaining per-space histories, reference counts and checkpoints. Keep the public API unchanged.

Verify a three-space page nesting against native OneNote and a fresh cold reopen. Cover every interrupted I/O, 514 paired revisions across the counter carry and both checkpoints, 130 core tests, 99 offline tests, 148 Python tests, Clippy, both iOS targets and 3,687 sanitizer executions.

Fix property copying stopping early on multi-reference arrays; cover all three streams with direct and nested regression cases.

Assisted-by: gpt-6-astra