Improve type hints with more specific return types and better generic usage

[ali90h]

Description

Enhance type safety across the codebase by improving type hints, using more specific return types, and better leveraging Python's generic type system.

Current Issues

• Some functions return object or overly broad types
• Generic types not used where appropriate
• Union types could be more specific
• Missing type hints in some newer functions

Proposed Solution

• Replace broad types (object, Any) with specific types
• Use TypeVar and generics for reusable functions
• Implement proper Protocol classes for interfaces
• Add missing type hints to all functions
• Use Literal types for string constants

Acceptance Criteria

• MyPy passes with strict mode enabled
• No use of Any or object except where truly necessary
• Generic types used appropriately for collections and functions
• All functions have complete type annotations
• Protocol classes defined for clear interfaces