#1059 Embedded auth tables have no row level security: auth 3.5.1 apply_tenant_rls() not present in highway_db_v2

EARS SPEC: - While Highway embeds the auth library, the auth_rbac tables shall have RLS enabled and forced with auth's tenant policies, or Highway shall document and test why tenant isolation for those tables is enforced elsewhere. - If RLS is not in force, then Highway's boot shall fail closed (as auth's own keycheck.verify_row_level_security does in auth/main.py). EVIDENCE (#1056 migrations run, 2026-10-23 22:47Z): 'apply_tenant_rls could not run (ProgrammingError); the boot check will refuse to serve if row level security is not in force' from auth/schema_reconcile.py. Read-only check: no function apply_tenant_rls in any schema of highway_db_v2. Highway never calls keycheck.verify_row_level_security (grep api enterprise engine scripts: 0), so the warning's promise does not hold in Highway. Pre-existing: true before this deploy too. Relevant to Phase 3 hosted auth (plan), which removes the embedded tables. SYNTHESIS: domain = multi-tenant DB isolation; concept = auth's own RLS migration (house tool, not reinvented). Alternatives: (a) run auth's migration that creates apply_tenant_rls, (b) accept until hosted-auth cutover with a boot assertion; decide with auth team.