* add test suite, mostly covers integration testing, tests are only backend side
* workflow runs the correct script
* workflow runs the correct script
* workflow runs the correct script
* unit tests incoming
* Fix multer silent rejections and error handler info leak
- Revert cb(null, false) to cb(new Error(...)) in auth.ts, collab.ts,
and files.ts so invalid uploads return an error instead of silently
dropping the file
- Error handler in app.ts now always returns 500 / "Internal server
error" instead of forwarding err.message to the client
* Use statusCode consistently for multer errors and error handler
- Error handler in app.ts reads err.statusCode to forward the correct
HTTP status while keeping the response body generic
