fix(cli): make top-level cp json-safe

[robertohluna]

Summary

• make top-level miosa cp honor --json for sandbox fallback uploads/downloads
• suppress host-resolution spinner, progress bars, and prose in JSON mode
• bump @miosa/cli to 1.0.42
• add regression coverage for cp --json and existing sandbox exec behavior

Verification

• npm run typecheck
• npm run build
• npm test -- --run test/commands/cp-ls-sandbox-alias.test.ts test/commands/sandbox.test.ts
• local live smoke: long sandbox exec stdout length 501, bash -c works, cp --json parses, ls --json sees uploaded file, sandbox cleanup destroyed