- implement method to convert tags to hashtags with capitalization and prefix
- enhance Draft struct to utilize hashtags in post processing

✅ test(draft): add unit tests for new hashtag functionality

- test hashtag conversion logic in taxonomies
- ensure draft processing correctly applies hashtags
- verify file creation in write_posts and cleanup operations

- relocate std::fs and std::path::Path imports to the test module for better organization

♻️ refactor(draft): improve struct initialization

- use struct update syntax to initialize Draft in test cases

♻️ refactor(front_matter): simplify hashtag formatting

- remove redundant format! braces for a cleaner code structure