Add option to import workflows from a folder

[LuD1161]

Add support for importing workflows directly from a folder using the CLI.
Currently, workflows need to be imported manually or through individual files. This feature should allow developers to bulk import all workflows located in a specified directory.

Proposed Behavior

In the .env file, users should be able to define the default import folder, for example:

WORKFLOW_IMPORT_DIR=./workflows

Acceptance Criteria

• Automatically uses WORKFLOW_IMPORT_DIR from .env if the flag is omitted.
• Provides clear logs for each imported workflow (success/failure).
• Handles invalid or duplicate workflow files gracefully.

Additional Notes

This feature simplifies developer onboarding and makes local development smoother — especially when managing multiple workflows across projects.

Depends on #43