cli metadata issues

There are some issues in cli metadata command:
- The cli display that the operation is finalized but it only wait for speculative execution
- For adding, when a same metadata is defined both via the config file and via the command line ; there are some unexpected effects

Start by locating the CLI metadata command and tracing its handling of speculative execution and metadata supplied through configuration and command-line arguments. Reproduce both reported cases, then add or update tests to verify that completion is reported only after the operation finishes and that duplicate metadata has defined behavior.

Written by the indexing model from the issue text.