Fix alignment button rendering, metadata updates, and dataset state

[BeckettFrey]

This pull request introduces a range of improvements across type annotations, runtime safety, and UI robustness in the codebase. The changes focus on enhancing type safety (with more explicit typing and runtime assertions), improving error handling, and making the GUI components more robust against potential None values. There are also some minor code cleanups and dependency updates.

Type Safety and Runtime Assertions:

• Added explicit type annotations in files like hooks/hook-nltk.py and src/voxkit/engines/base.py to clarify expected data types. [1] [2]
• Introduced runtime assertions to ensure variables are not of unexpected types (e.g., checking that metadata and messages are not strings before accessing as dicts) in engine and startup routines. [1] [2] [3] [4] [5] [6]
• Added an assertion to ensure color values are not None before use in default_analyzer.py.

GUI Robustness and Cleanups:

• Improved PyQt6 GUI components to check for None before accessing or modifying headers, views, or parent widgets, preventing potential runtime errors. [1] [2] [3] [4] [5] [6] [7]
• Refactored variable names for clarity (e.g., parent to _parent_widget in dialogs) and fixed minor typos in comments. [1] [2]

Dependency and Configuration Updates:

• Updated development dependencies in pyproject.toml (added types-PyYAML) and enhanced mypy configuration for stricter type checking and better diagnostics. [1] [2]

Minor Code Cleanups and Imports:

• Cleaned up and reordered imports for consistency and removed unused imports in several files. [1] [2] [3] [4]
• Standardized string formatting and download calls for NLTK resources. [1] [2]

Other Fixes:

• Added # type: ignore for a type assignment in a typeguard patch and made minor stylistic changes for code clarity. [1] [2] [3] [4]

These changes collectively improve the maintainability, reliability, and clarity of the codebase.