Integrate Canvas, Piazza and Google Classrooms API to add courses and deadlines automatically

[amaydixit11]

[RafaelPulzi]

Hi! I’d like to work on this issue.

Before opening a PR, I’d like to scope it in a way that fits the current architecture of the project. My plan is to introduce a provider-agnostic LMS integration layer, import external courses as local private courses, and sync external assignments into the existing local assignment flow so the current deadlines UI continues to work without a parallel implementation.

For the first implementation pass, I’d like to build the foundation around the documented Google Classroom and Canvas APIs, then keep Piazza behind the same adapter boundary. I have not found a stable public developer API for Piazza comparable to the other two, so I’d prefer to avoid coupling the project to unofficial endpoints unless that direction is explicitly preferred by the maintainers.

[amaydixit11]

Hey @RafaelPulzi
LGTM, go ahead!