Fix DAS server http.Server.Addr and add graceful shutdown timeout

[viktorking7]

Description

• What:

  • Remove http:// scheme from http.Server.Addr (use host:port).
  • Add 10s timeout to Shutdown to avoid indefinite hangs.

• Why:

  • Addr expects host:port; including a scheme is incorrect and misleading.
  • Bounded graceful shutdown improves reliability under stuck handlers.

• Impact:

  • More correct server configuration and safer shutdown behavior.
  • No behavior change for Serve(listener) path.