separate account settings from shop settings

- Create dedicated /admin/account page for user account management
- Move email, password, and 2FA settings from /admin/settings
- Add Account link to top of admin sidebar navigation
- Add TOTP-based two-factor authentication with NimbleTOTP
- Add TOTP verification LiveView for login flow
- Add AccountController for TOTP session management
- Remove Advanced section from settings (duplicated in dev tools)
- Remove user email from sidebar footer (replaced by Account link)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

lib/berrypod_web/router.ex

@@ -143,6 +143,11 @@ defmodule BerrypodWeb.Router do
     post "/settings/email/test", EmailSettingsController, :test
     post "/settings/from-address", SettingsController, :update_from_address
     post "/settings/stripe/signing-secret", SettingsController, :update_signing_secret
+    # Account TOTP routes (session-based for mobile reconnect persistence)
+    post "/account/totp/start", AccountController, :start_totp_setup
+    post "/account/totp/cancel", AccountController, :cancel_totp_setup
+    get "/account/totp/complete", AccountController, :complete_totp_setup
+    post "/account/totp/dismiss-codes", AccountController, :clear_backup_codes
     post "/navigation", NavigationController, :save
     post "/providers", ProvidersController, :create
     post "/providers/:id", ProvidersController, :update
@@ -165,6 +170,7 @@ defmodule BerrypodWeb.Router do
       live "/providers/:id/edit", Admin.Providers.Form, :edit
       live "/settings", Admin.Settings, :index
       live "/settings/email", Admin.EmailSettings, :index
+      live "/account", Admin.Account, :index
       live "/pages", Admin.Pages.Index, :index
       live "/pages/new", Admin.Pages.CustomForm, :new
       live "/pages/:slug/settings", Admin.Pages.CustomForm, :edit
@@ -208,9 +214,11 @@ defmodule BerrypodWeb.Router do
       live "/users/register", Auth.Registration, :new
       live "/users/log-in", Auth.Login, :new
       live "/users/log-in/:token", Auth.Confirmation, :new
+      live "/users/totp", Auth.TotpVerification, :new
     end
 
     post "/users/log-in", UserSessionController, :create
+    post "/users/verify-totp", UserSessionController, :verify_totp
     delete "/users/log-out", UserSessionController, :delete
   end