refactor: remove mobile-callback bridge page (Task 13)

app/api/auth/mobile-callback/route.ts

@@ -1,35 +0,0 @@
-import { auth } from "@/lib/auth"
-import { NextRequest } from "next/server"
-
-/**
- * Mobile OAuth bridge page.
- *
- * After a social OAuth flow completes in the mobile WebBrowser,
- * Better Auth redirects here with the session cookie set.
- * We extract the session token and redirect to the app's
- * deep link scheme so the mobile app can store the token.
- */
-export async function GET(request: NextRequest) {
-  try {
-    const session = await auth.api.getSession({
-      headers: request.headers,
-    })
-
-    if (!session) {
-      // No session found — redirect to app with error
-      const errorUrl = new URL("deckyvault://auth/callback")
-      errorUrl.searchParams.set("error", "session_not_found")
-      return Response.redirect(errorUrl.toString())
-    }
-
-    const token = session.session.token
-    const callbackUrl = new URL("deckyvault://auth/callback")
-    callbackUrl.searchParams.set("token", token)
-
-    return Response.redirect(callbackUrl.toString())
-  } catch {
-    const errorUrl = new URL("deckyvault://auth/callback")
-    errorUrl.searchParams.set("error", "callback_error")
-    return Response.redirect(errorUrl.toString())
-  }
-}