[PeaBrane]

Summary

Fresh checkouts lack the ignored research notes, references, ledger, and unpublished paper sources. Add a filtered snapshot/restore helper and document how users with existing private GitHub access can restore that context.

Restoration checks every incoming path before copying, refuses differing local files and public tracked files, retains existing local datasets, and removes its temporary clone. Snapshots retain sources, PDFs, figures, and small text evidence while omitting bulk computational artifacts and environments.

Validation

• 13 regression tests cover snapshot selection, idempotent restores, conflict protection, public tracked files, symlinks, access checks, and temporary-clone cleanup.
• The filtered private snapshot passes its ledger checker with intentionally absent artifacts reported as informational availability diagnostics.
• Ruff checks and formatting pass; repository commit hooks pass.