♻️ Rework authentication

- Move login endpoint `/login` to `/auth/login`
- Add logout route `/auth/logout`
- Add `/api/token` endpoint and `?token=` query parameter for auth
- Refactor `auth.js`

server/index.js

@@ -34,7 +34,8 @@ new Parser(
 );
 
 // Create new Auth class to store sessions
-app.post("/login", auth.login);
+app.post("/auth/login", auth.login);
+app.get("/auth/logout", auth.logout);
 // Check login for every API request
 app.use("/api", auth.checkLogin);
 // Provide check endpoint so the frontend
@@ -48,6 +49,7 @@ app.get("/api/timetable", getTimetable);
 app.get("/api/substitutions", getSubstitutions);
 app.get("/api/history", getHistory);
 app.get("/api/classes", getClasses);
+app.post("/api/token", auth.token);
 // Respond with 400 for non-existent endpoints
 app.get("/api/*", (_req, res) => {
   res.sendStatus(400);