CC-489 lock script domain Phase 0 contracts

[screenleon]

Summary

• archive terminal backlog entries before the planning slice
• define the complete script-domain ownership and current-to-target path inventory
• record variable ownership, precedence, propagation, side effects, and static consumers
• add a ratchet linter plus regression coverage and register both with the shared test runner

Why

CC-489 is not a bulk file move. Moving shell modules can change repository-root derivation, ambient environment precedence, child-process variables, and filesystem side effects. This Phase 0 PR locks those contracts before any production relocation.

Phase 1 remains blocked on CC-451, CC-490, and CC-491 contract convergence.

Validation

• PR gate: GO (gate-20260715-020701-0a527a)
• bash scripts/lint-script-domain-inventory.sh
• bash scripts/test-script-domain-inventory.sh — 10/10
• bash scripts/test-run-tests.sh — 17/17
• bash scripts/test-run-all-tests.sh — 34/34
• bash scripts/test-archive-closed-backlog.sh — 15/15
• bash scripts/test-check-docs-freshness.sh — 21/21
• bash scripts/lint-scripts.sh
• bash scripts/lint-test-docstrings.sh
• pmctl backlog lint
• git diff --check

Impact

No production script is relocated in this PR. The new TSV files are planning contracts and are not runtime registries.