Renamed the 'Article' domain to 'Post' in order to better reflect the purpose and utility of the object. The change involved renaming all related use cases, classes, and other references from 'Article' to 'Post' and updating all functions and data types to work with Posts instead of Articles.
This commit adds a line to set the "DB_FILE" environment variable in tests. This ensures that tests are always using "test.db" for database related operations, aligning testing environment accurately which guarantees consistent results.
Florian Sylvain