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

.editorconfig

@@ -0,0 +1,18 @@
+root = true
+
+[*]
+indent_style = space
+indent_size = 4
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+[*.yaml]
+indent_size = 2
+
+[*.yml]
+indent_size = 2
+
+[Makefile]
+indent_style = tab