[EauDoon]

Problem

Individually bounded stage files could produce a portable bundle larger than the replay limit. Saving succeeded and replaced latest.json, but export/replay then failed. A persistence failure inside a stage handler could also be mistaken for a component failure and publish a smaller replacement case.

Change

• Measure exact UTF-8 sizes for formatted stage files, manifest, report, and the combined portable bundle before creating a run directory.
• Reject oversized cases without truncating evidence or replacing the previous latest pointer.
• Propagate finalization failures outside component-error handling.

Verification

• npm run check: 212 tests passed, syntax and version gates passed.
• Regression coverage includes combined-stage size, formatting expansion, multibyte input, exact-limit acceptance, and five end-to-end stage outcomes preserving the previous case.
• Independently reviewed and checked before publication.

No component pins, release tags, deployment settings, or live connectors change.