* defer committing workspace directory path changes until blur or enter
Introduce draft state for the workspace directory path input, only
committing the changes on blur, Enter, or Browse completion. This
prevents the backend from creating incomplete directory path prefixes on
disk with `mkdir` during intermediate typing states.
* Fix agent-hooks test mock and clean up unused imports
* Update the RuntimeClient mock in agent-hooks test to return a fully
typed instance with the correct schema, eliminating type assertions.
* Remove an unused React import in WorkspaceDirectorySetting test.