- Renamed 'it should contain' steps to 'the container types should contain' for specificity
- Updated execution_environment.feature to use the new step names
- This fixes the AmbiguousStep error that was preventing unit tests from running
Add ExecutionEnvironment enum (host/container) to domain models, implement
execution environment resolution with priority chain (tool > plan > project
> default), wire the tool runner to check execution_environment before
execution, and add CLI flags to plan use/execute and project context set.
When container is selected but no container resource is available, a clear
ContainerUnavailableError is raised with an actionable message.
Closes#512