feat: initial project scaffolding

Set up the daena project with:
- pyproject.toml with all core and dev dependencies
- .python-version pinned to 3.13.5
- .gitignore for Python/uv/OS artifacts
- .editorconfig for consistent formatting
- .env.example for deployment configuration
- src/daena package skeleton with version
- uv-managed virtual environment

.gitignore

@@ -0,0 +1,34 @@
+# Python
+__pycache__/
+*.py[cod]
+*.egg-info/
+dist/
+build/
+*.egg
+.venv/
+venv/
+
+# uv
+.lock
+uv.lock
+
+# IDE
+.vscode/
+.idea/
+*.swp
+*.swo
+*~
+
+# OS
+.DS_Store
+Thumbs.db
+
+# Project
+data/
+logs/
+*.pid
+*.sock
+
+# Env
+.env
+.env.local