Add missing patterns to .gitignore for improved completeness

[smoparth]

Summary

The current .gitignore is missing several common Python and editor-specific patterns. While the core patterns (e.g., __pycache__/, .coverage, *.egg-info/, .venv/, build/, dist/) are well covered, adding the missing ones aligns more closely with the GitHub Python .gitignore template and improves compatibility with AI-assisted development tools.

Current State

The .gitignore covers approximately 5 of the 12 recommended language-specific patterns (per an agentready assessment).

Suggested Additions

# Compiled bytecode (supplements __pycache__/)
*.py[cod]
*$py.class

# Editor/IDE directories
.vscode/
.idea/

# Editor swap/temp files
*.swp
*.swo
*~

# Environment files
.env
.env.local

Notes

These patterns are safe to add and have no impact on existing workflows.

[dhellmann]

This seems fine, please go ahead and submit a PR.