Add createDirectoryIfNeeded method to ApplicationRoot

[denizguney]

Implement a utility method to ensure the application root directory and any intermediate directories exist on disk.

Adds a utility method to ensure the application root directory exists on disk, preventing runtime path resolution errors. Related to issue #2215

Type of Change

• Bug fix
• New feature
• Breaking change
• Documentation update

Motivation and Context

[Why is this change needed?]

Testing

• Tested locally
• Added/updated tests
• Added/updated docs

[jglogan]

Why is this needed? ApplicationRoot isn't meant to mutate anything.

[denizguney]

"Although ApplicationRoot itself is primarily designed to represent path structures, ensuring that the root directory and its intermediate paths exist on disk prevents runtime path resolution and I/O errors during container initialization. This utility method safely guarantees that the required directory structure is initialized prior to execution, avoiding unhandled exceptions when components attempt to write or access path targets."