refactor: deduplicate code and extract logic in widgets, enums, and context/cursor

[surgiie]

This pull request introduces several improvements and refactorings to the codebase, focusing on code reuse, maintainability, and UI consistency. The most significant changes include extracting tag color logic into a reusable class, introducing a trait for rendering centered dialogs, refactoring urgency option handling, and simplifying cursor management. Below are the most important changes grouped by theme:

Tag color handling and code reuse:

• Extracted tag color palette and logic from Todo and TodoDetailWidget into a new reusable class TagColors, which provides methods for assigning consistent colors to tags by name or index. (src/Support/TagColors.php, src/Support/Todo.php, src/Widgets/TodoDetailWidget.php) [1] [2] [3] [4] [5] [6]

UI consistency and code reuse for dialogs:

• Added a new trait RendersAsDialog to encapsulate the logic for rendering widgets as centered dialogs with horizontal margins, and refactored HelpWidget and TodoDetailWidget to use this trait for consistent dialog appearance. (src/Widgets/Concerns/RendersAsDialog.php, src/Widgets/HelpWidget.php, src/Widgets/TodoDetailWidget.php) [1] [2] [3] [4] [5]

Urgency option handling improvements:

• Added a static method selectOptions() to the TodoUrgency enum to generate a value-to-label map for select prompts, and refactored related code to use this method for better maintainability. (src/Support/Enums/TodoUrgency.php, src/Support/DataManager.php) [1] [2] [3]

Cursor management and code simplification:

• Added a static inactive() constructor to the Cursor class for clearer intent, and refactored usage throughout the codebase to use this method instead of manually instantiating inactive cursors. (src/Support/Cursor.php, src/Widgets/MainWidget.php) [1] [2] [3]
• Consolidated repeated paginator update logic in MainWidget into a new helper method updatePaginatorForType(), reducing code duplication and improving maintainability. (src/Widgets/MainWidget.php) [1] [2] [3] [4] [5] [6]

Other improvements:

• Made DATA_FILE_NAME in DataManager public and updated references to use it instead of a duplicate constant in Context. (src/Support/DataManager.php, src/Support/Context.php) [1] [2] [3]
• Simplified container removal logic in the docker script by using docker rm -f and docker container inspect. (docker)