ISO Readiness Enumerate

Use to enumerate ISO requirements from a registry attached to the workspace (clause projections under /workspace/local/registries/{registryId}/{section}/{clauseLabel}/{clauseLabel}.md) and write the readiness manifest marking each requirement ready, skip_fresh, or skip_bad_record. MUST run bundled lib/requirements.py — never regenerate the enumerator. Manifest.requirements is an array (not a map). Deterministic Python only — no cortex_search.