feat: add hello world function with comprehensive tests

[Wirasm]

Summary

This PR adds a simple hello world function implementation that serves as a reference for Python 3.12+ best practices, including full type safety, Google-style docstrings, and comprehensive testing.

Changes

• feat: add hello world function with comprehensive tests
• docs: add PRP for hello world function feature
• chore: update uv.lock

Implementation Details

This implementation follows the specification in PRPs/features/completed/hello-world-function.md and demonstrates:

• Python 3.12+ type hints with modern syntax (str type hints)
• Google-style docstrings with Args, Returns, and Examples sections
• Comprehensive unit tests covering default behavior, custom names, edge cases, and output verification
• KISS principle - simple, maintainable code without unnecessary complexity
• Full type safety - passes strict mypy checking

Key Files Added

• hello_world_test_from_archon.py - Main implementation with greet() function
• dylan/tests/test_hello_world_test_from_archon.py - Comprehensive unit tests
• PRPs/features/completed/hello-world-function.md - Complete PRP documentation

Technical Details

The greet() function:

• Accepts an optional name parameter (defaults to "World")
• Prints a greeting message to stdout
• Returns the greeting string for programmatic use
• Includes full type annotations using Python 3.12 syntax
• Has a comprehensive Google-style docstring with examples

Testing

• All existing tests pass
• New tests added with 100% coverage of new code
• Manual testing completed
• Linting checks pass (ruff)
• Type checking passes (mypy --strict)
• All unit tests pass with 5 test cases covering default behavior, custom names, return values, and edge cases

Validation Passed

All validation commands executed successfully:

• uv run ruff check - Passed
• uv run mypy --strict - Passed
• uv run pytest -v - All tests passed

Related PRP

See: PRPs/features/completed/hello-world-function.md