chore: import upstream snapshot with attribution

.gitignore

@@ -0,0 +1,61 @@
+# Python
+__pycache__/
+*.py[cod]
+*$py.class
+*.so
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+/lib/
+/lib64/
+parts/
+sdist/
+var/
+wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+
+# Virtual environments
+venv/
+ENV/
+env/
+.venv
+
+# IDE
+.vscode/
+.idea/
+*.swp
+*.swo
+.DS_Store
+*.tmp
+
+# Project specific
+*.log
+.env
+.env.local
+*.lock
+
+# Spec Kit-specific files
+.genreleases/
+*.zip
+sdd-*/
+docs/dev
+
+# Extension system
+.specify/extensions/.cache/
+.specify/extensions/.backup/
+.specify/extensions/*/local-config.yml
+
+# The following directories/file are intentionally ignored so that they are not accidentally
+# committed to the repository. They contain the scaffolding `specify init --integration copilot`
+# does and they are meant for dogfooding Spec Kit during its own feature development.
+.github/agents/
+.github/prompts/
+.github/copilot-instructions.md
+.specify/
+specs/