Remove legacy backend

[humphd]

As we prepare to migrate away from the legacy backend, and toward a pure microservices approach, I'd like to switch the repo around a little bit. Specifically:

• create src/legacy
• move test/ to src/legacy/test
• move contents of src/backend to src/legacy/src
• create a package.json in src/legacy
• move all aspects of the root package.json that are specific to the legacy backend to src/legacy/package.json (e.g., all dependencies for the backend should go in the root package).
• add src/legacy to the pnpm workspace list
• update eslintrc.js so it knows about src/legacy
• update test/jest.config.js to point to the correct place
• Move and update the Dockerfile for the backend out of the root and into src/legacy/Dockerfile
• update any references in docs or other files that use src/backend to point to the new locations
• update relative links from tests or other source files, so things still work
• update .vscode/launch.json
• etc

When this is done, it's going to be easier to use turborepo, since all of our projects will be workspaces, and there will be nothing in the root except our tooling.

It will also mean that all of our sub-projects will use the same general layout, with their own src, test, Dockerfile, etc.

Later, we'll be able to dump src/legacy as a whole.

[HyperTHD]

This sounds like alot of work that's really unnecessary. The only service blocking the backend folder from being deleted is the parser service. I get wanting to make more use of turborepo, but considering it'll eventually be deleted, this just sounds like work we can ignore no?

[humphd]

It's a fair question. The reason I think that this is a valuable exercise is that it helps the current team to define the boundaries of the old vs. new code. Doing this work will be necessary in order to remove the old code, and if we don't know where it is, it's hard to do. Getting rid of the backend isn't quite as simple as turning on the parser service and deleting src/backend, as you can see above.

[tpmai22]

@TueeNguyen would be great if you can shred some light on this.

[TueeNguyen]

We're removing the backend instead of isolating it

[manekenpix]

Since the legacy backend was removed, I think this is no longer needed.

[sirinoks]

WE DID IT