e862b82322
npm treats optionalDependencies failures as non-fatal, so a transient network blip fetching claude-code's platform-native binary during `npm install -g` left a stub CLI in an image that still "built" successfully — then got baked into the Docker/Container layer cache until forced to rebuild. Post-build smoke test (provider-declared argv, run in a throwaway container of the freshly built image) fails the launch loudly instead of shipping a broken image; --no-cache gives an escape hatch to force a from-scratch rebuild. Closes #353.