This commit introduces Doxygen for documentation generation and a Gitea
workflow for continuous integration.
- Adds a `Doxyfile` to configure Doxygen to build a documentation
website with diagrams.
- Updates `AGENTS.md` to require Doxygen-compatible comments for all
code.
- Adds Doxygen comments to existing C++ source files to comply with
the new standard.
- Creates a Gitea workflow (`.gitea/workflows/build.yml`) that:
- Builds the project on every push.
- Generates Doxygen documentation.
- Uploads the compiled library and the documentation website as
artifacts.
google-labs-jules[bot]