Support tilde (~) expansion in template paths

[mathiusj]

Problem

Currently, the template() method in DSL workflows uses Pathname which does not automatically expand ~ for the user's home directory.

While this is a niche use case, supporting it would allow workflows to reference templates in a user's home directory, which could be useful for shared personal configuration or reusable prompt libraries.

Example

# Currently doesn't work:
chat { template("~/my_prompts/greeting.md.erb", name: "World") }

# Would need to use:
chat { template(File.expand_path("~/my_prompts/greeting.md.erb"), name: "World") }

Related

• PR Enable shorthand template syntax with workflow directory resolution #582 - template method with workflow directory resolution
• Review comment: Enable shorthand template syntax with workflow directory resolution #582 (comment)