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>

test/berrypod_web/controllers/user_session_controller_test.exs

@@ -18,7 +18,7 @@ defmodule BerrypodWeb.UserSessionControllerTest do
         })
 
       assert get_session(conn, :user_token)
-      assert redirected_to(conn) == ~p"/admin/setup"
+      assert redirected_to(conn) == ~p"/setup"
 
       # Now do a logged in request and assert on the page content
       conn = get(conn, ~p"/admin/settings")
@@ -39,7 +39,7 @@ defmodule BerrypodWeb.UserSessionControllerTest do
         })
 
       assert conn.resp_cookies["_berrypod_web_user_remember_me"]
-      assert redirected_to(conn) == ~p"/admin/setup"
+      assert redirected_to(conn) == ~p"/setup"
     end
 
     test "logs the user in with return to", %{conn: conn, user: user} do
@@ -80,7 +80,7 @@ defmodule BerrypodWeb.UserSessionControllerTest do
         })
 
       assert get_session(conn, :user_token)
-      assert redirected_to(conn) == ~p"/admin/setup"
+      assert redirected_to(conn) == ~p"/setup"
 
       # Now do a logged in request and assert on the page content
       conn = get(conn, ~p"/admin/settings")
@@ -99,7 +99,7 @@ defmodule BerrypodWeb.UserSessionControllerTest do
         })
 
       assert get_session(conn, :user_token)
-      assert redirected_to(conn) == ~p"/admin/setup"
+      assert redirected_to(conn) == ~p"/setup"
       assert Phoenix.Flash.get(conn.assigns.flash, :info) =~ "User confirmed successfully."
 
       assert Accounts.get_user!(user.id).confirmed_at