Cloud consent

Explicit consent is required before sending data to cloud providers.

# Consent to cloud
ship-spec planning --cloud-ok
ship-spec productionalize --cloud-ok

# Force local-only execution
ship-spec planning --local-only
ship-spec productionalize --local-only

Consent is persisted in .ship-spec/consent.json. Local-only mode keeps all processing on your machine (Ollama + local embeddings).