Two amendments from Phase 4 implementation (2026-04-17):
1. New rationale: Nushell parses use statements inside function bodies
at module-load time, not call time. Subprocess boundary is the only
true lazy-load mechanism. Confirmed empirically.
2. Single-entry provisioning-cli.nu tested and rejected for hot paths
(3.1s vs 0.08-0.15s thin handlers). All 15 dispatcher wrappers fire
at module-load time regardless of which command runs.
3. Constraints amended: bash-wrapper-has-no-runner-reference updated to
permit provisioning-cli.nu fallback; new universal-fallback-is-
transitional constraint documents 22 unmapped commands as migration
debt; every-registry-command-has-thin-handler made directional.
