Linting/Formatting of scripts folder

[Snuffy2]

This pull request focuses on code quality improvements in the scripts folder, applying linting, formatting, and restructuring to align with the project's standards outlined in AGENTS.md.

Key Changes:

Enhanced llm_health_dashboard.py:

• Added comprehensive type annotations using modern Python 3.11+ syntax (e.g., list[ModelData] instead of List[ModelData])
• Added detailed NumPy-style docstrings to all functions and classes
• Replaced print() statements to stderr with logger.error() using loguru
• Improved import organization and added missing imports (e.g., collections.abc.Generator)
• Enhanced error handling and code structure

Restructured Test Suite:

• Moved scripts/test_llm_contracts.py to test_llm_contracts.py
• Converted the standalone test script to use pytest framework with proper fixtures and test methods
• Added integration test markers and server availability checks
• Improved type annotations and docstrings throughout
• Added init.py with package documentation

These changes bring the scripts folder in line with the project's coding standards, improving code quality, type safety, and testability without altering core functionality.