Mountable LiveView preview and operator surfaces for mailglass.

The canonical v1.x admin contract lives in mailglass_admin/docs/api_stability.md.

The stable package promise is narrow:

• MailglassAdmin.Router is the stable mount surface.
• MailglassAdmin.Auth is the stable adopter-owned auth seam.
• version/0 is a stable package helper.

LiveView implementation modules, DOM/CSS shape, preview plumbing, and internal mount hooks remain internal even when framework wiring requires them to stay reachable.

Quick start

Add to your adopter app's lib/my_app_web/router.ex:

import MailglassAdmin.Router

if Application.compile_env(:my_app, :dev_routes) do
  scope "/dev" do
    pipe_through :browser
    mailglass_admin_routes "/mail"
  end
end

Restart mix phx.server, visit /dev/mail. Done.

See MailglassAdmin.Router.mailglass_admin_routes/2 and MailglassAdmin.Router.mailglass_operator_routes/2 for options.