Preserve retained publication proofs in exact acceptance exports

[docxology]

Exact-main release acceptance stopped at Textbook because its ordinary fork copier intentionally omits seven historical publication proofs under rendered/, while the acceptance archive requires the complete public snapshot. Acceptance exports now supplement only those missing root proof members from held source bytes, then renew the embedded manifest and pass the unchanged independent archive oracle. Ordinary fork copies retain their exclusions; missing authored inputs, changed bytes and extra members still fail.

Add genuine export and filesystem fault controls, bind the new cases to the existing Git prerequisite, and preserve every previous test classification and prerequisite definition. Renew all 25 canonical validation snapshots for the shared infrastructure change and update measured counts and release-intent notes. Snapshot renewal establishes rendered consistency; final release acceptance remains required on the merged revision.

Validation:

• 66 selected installed-acceptance/copy tests passed; 25 slow cases deselected by the declared default selection.
• All 25 real exact-source acceptance exports passed, including Textbook's seven retained proof members.
• Full public Ruff, format and mypy checks passed; lexical no-mocks and semantic inventory passed with zero dependency replacements.
• Canonical validation passed for all 25 exemplars; public tracking, generated artifact and module budget guards passed.
• Fresh independent source and policy classification review found no actionable defects.
• Final canonical census and independent policy readback passed: 12,216 families / 14,948 cases, with every prior classification and all 29 prerequisite definitions preserved.
• Strict staged rendered publication audit passed for all 25 exemplars with zero findings.