AAI-179: initialize FastAPI project with basic structure and tests

[minh-biocommons]

Description

AAI-178: Setup aai-backend project with uv

AAI-179: Setup aai-backend project with FastAPI

This PR bootstraps the new aai-backend project using uv to ensure reproducible environments and modern Python dependency management. It includes a minimal FastAPI structure and test scaffolding to support upcoming features.

Changes

• uv-based setup (e.g., uv venv, dependency management)
• Basic FastAPI app structure (main.py, routers/, schemas/)
• pytest-based test framework with sample test cases
• Initial Pydantic schema definitions
• Setup Github Actions workflow for tests

Checklist

• I have commented my code, particularly in hard-to-understand areas
• I have added unit / integration tests that prove my fix is effective or that my feature works
• I have run all tests locally and they pass
• I have updated the documentation (if applicable)

[amandazhuyilan]

Overall looks great! Would you also be able to set up running of the pytests with Github Actions in this pull request? Then we will have a properly set up project. Thank you!

[marius-mather]

A few minor comments on schemas, but we also want to make sure we're properly making use of uv to manage dependencies - this will make it easier to work with down the line. Try installing all deps via uv, and update the readme to reflect using uv to set up the virtual environment.

[marius-mather]

The most useful documentation is going to be here: Working on projects and here: Managing dependencies

[marius-mather]

A couple of suggestions to make sure we get started on the right foot with our dependency management

[marius-mather]

Looking good now, thanks!

[amandazhuyilan]

Added 2 more small suggestions on the README - ready to go!