Operations could only inline schemas: the generated document had no
components section, so #/components/... references dangled. OpenAPIMixin
and generate_spec now accept a components mapping (merged verbatim into
the document) and kaya.openapi exports schema_ref() to build
#/components/schemas/<name> references. Component references are
validated at generation time and unknown ones raise ValueError.
- New packages/kaya-openapi with OpenAPIMixin, @operation decorator,
and generate_spec() that walks the routing tree
- Enables kaya-core's Tree.register to expose the original handler
callback as an instance attribute for metadata introspection
- Registers GET /openapi.json and GET /docs (Swagger UI) routes
- Supports and path parameters, docstring
descriptions, @operation metadata, and excludes wildcard/WS routes
- Adds example/openapi.py, updates CI, README, and requirements
woggioni