add setup onboarding page, dashboard launch checklist, provider registry

- new /setup page with three-section onboarding (account, provider, payments)
- dashboard launch checklist with progress bar, go-live, dismiss
- provider registry on Provider module (single source of truth for metadata)
- payments registry for Stripe
- setup context made provider-agnostic (provider_connected, theme_customised, etc.)
- admin provider pages now fully registry-driven (no hardcoded provider names)
- auth flow: fresh installs redirect to /setup, signed_in_path respects setup state
- removed old /admin/setup wizard
- 840 tests, 0 failures

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

lib/berrypod_web/router.ex

@@ -140,6 +140,16 @@ defmodule BerrypodWeb.Router do
     end
   end
 
+  # Setup page — minimal live_session, no theme/cart/search hooks
+  scope "/", BerrypodWeb do
+    pipe_through [:browser]
+
+    live_session :setup,
+      on_mount: [{BerrypodWeb.UserAuth, :mount_current_scope}] do
+      live "/setup", Setup.Onboarding, :index
+    end
+  end
+
   ## Authentication routes
 
   # Admin pages with sidebar layout
@@ -153,7 +163,6 @@ defmodule BerrypodWeb.Router do
         {BerrypodWeb.AdminLayoutHook, :assign_current_path}
       ] do
       live "/", Admin.Dashboard, :index
-      live "/setup", Admin.Setup, :index
       live "/orders", Admin.Orders, :index
       live "/orders/:id", Admin.OrderShow, :show
       live "/products", Admin.Products, :index