Build installer and management site from spec

src/server/middleware/auth.ts

@@ -0,0 +1,15 @@
+import { NextFunction, Request, Response } from 'express'
+
+declare module 'express-session' {
+  interface SessionData {
+    userId?: string
+  }
+}
+
+export function requireAuth(req: Request, res: Response, next: NextFunction): void {
+  if (req.session.userId == null) {
+    res.redirect('/op')
+    return
+  }
+  next()
+}