rework email settings for true progressive enhancement

Render all adapter field sections in the form with CSS :has(:checked)
controlling visibility. Selecting a provider instantly shows its config
fields — no JS, no page reload, no server round-trip needed.

- Render all 6 adapter configs with data-adapter attribute
- CSS :has(:checked) show/hide rules per adapter in admin stylesheet
- Namespace field names per adapter (email[brevo][api_key] etc)
- Drop 4 transactional-only providers (Resend, Postmark, Mailgun, MailPace)
- Remove noscript "Switch provider" button and controller redirect workaround
- Remove configured_adapter hidden input tracking
- Hide JS-only test email button for no-JS users via noscript style
- LiveView progressively enhances with async save and test email

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

test/berrypod_web/live/admin/email_settings_test.exs

@@ -33,27 +33,17 @@ defmodule BerrypodWeb.Admin.EmailSettingsTest do
       # Provider names rendered as radio cards
       assert html =~ "Brevo"
       assert html =~ "Mailjet"
-      assert html =~ "MailPace"
       assert html =~ "Postal"
     end
 
-    test "shows all three provider groups", %{conn: conn} do
+    test "shows providers and advanced section", %{conn: conn} do
       {:ok, _view, html} = live(conn, ~p"/admin/settings/email")
 
-      # All-email providers
-      assert html =~ "Popular providers"
       assert html =~ "Brevo"
       assert html =~ "SendGrid"
       assert html =~ "Mailjet"
       assert html =~ "MailerSend"
 
-      # Transactional providers
-      assert html =~ "Transactional only"
-      assert html =~ "Resend"
-      assert html =~ "Postmark"
-      assert html =~ "Mailgun"
-      assert html =~ "MailPace"
-
       # Advanced in details
       assert html =~ "Already have your own email server?"
       assert html =~ "SMTP"
@@ -64,10 +54,20 @@ defmodule BerrypodWeb.Admin.EmailSettingsTest do
       {:ok, _view, html} = live(conn, ~p"/admin/settings/email")
 
       assert html =~ "needs an email provider"
-      assert html =~ "300 emails/day free"
     end
 
-    test "selecting a provider shows its config fields", %{conn: conn} do
+    test "renders all adapter field sections in the form", %{conn: conn} do
+      {:ok, _view, html} = live(conn, ~p"/admin/settings/email")
+
+      # All adapters have their config sections rendered (CSS controls visibility)
+      assert html =~ ~s(data-adapter="brevo")
+      assert html =~ ~s(data-adapter="sendgrid")
+      assert html =~ ~s(data-adapter="mailjet")
+      assert html =~ ~s(data-adapter="smtp")
+      assert html =~ ~s(data-adapter="postal")
+    end
+
+    test "selecting a provider updates via phx-change", %{conn: conn} do
       {:ok, view, _html} = live(conn, ~p"/admin/settings/email")
 
       # Select SMTP via form change (radio inputs fire phx-change)
@@ -76,35 +76,9 @@ defmodule BerrypodWeb.Admin.EmailSettingsTest do
         |> form("form[phx-change=\"form_change\"]", %{email: %{adapter: "smtp"}})
         |> render_change()
 
+      # SMTP fields are always rendered; check the step title changes
       assert html =~ "Server host"
       assert html =~ "Port"
-      assert html =~ "Username"
-      assert html =~ "Password"
-    end
-
-    test "selecting a different provider shows different fields", %{conn: conn} do
-      {:ok, view, _html} = live(conn, ~p"/admin/settings/email")
-
-      # Select Brevo which needs just an api_key
-      html =
-        view
-        |> form("form[phx-change=\"form_change\"]", %{email: %{adapter: "brevo"}})
-        |> render_change()
-
-      assert html =~ "API key"
-      assert html =~ "Brevo"
-    end
-
-    test "selecting a transactional provider shows its config", %{conn: conn} do
-      {:ok, view, _html} = live(conn, ~p"/admin/settings/email")
-
-      html =
-        view
-        |> form("form[phx-change=\"form_change\"]", %{email: %{adapter: "resend"}})
-        |> render_change()
-
-      assert html =~ "API key"
-      assert html =~ "Resend"
     end
 
     test "saving config persists settings", %{conn: conn} do
@@ -115,11 +89,11 @@ defmodule BerrypodWeb.Admin.EmailSettingsTest do
       |> form("form[phx-change=\"form_change\"]", %{email: %{adapter: "brevo"}})
       |> render_change()
 
-      # Submit with an API key
+      # Submit with namespaced fields: email[brevo][api_key]
       html =
         view
         |> form("form[phx-submit=\"save\"]", %{
-          email: %{adapter: "brevo", api_key: "xkeysib-abc123def456"}
+          email: %{adapter: "brevo", brevo: %{api_key: "xkeysib-abc123def456"}}
         })
         |> render_submit()
 
@@ -138,7 +112,9 @@ defmodule BerrypodWeb.Admin.EmailSettingsTest do
       # Submit without API key
       html =
         view
-        |> form("form[phx-submit=\"save\"]", %{email: %{adapter: "brevo", api_key: ""}})
+        |> form("form[phx-submit=\"save\"]", %{
+          email: %{adapter: "brevo", brevo: %{api_key: ""}}
+        })
         |> render_submit()
 
       assert html =~ "API key is required"
@@ -154,7 +130,7 @@ defmodule BerrypodWeb.Admin.EmailSettingsTest do
       html =
         view
         |> form("form[phx-submit=\"save\"]", %{
-          email: %{adapter: "smtp", relay: "smtp.example.com", port: "abc"}
+          email: %{adapter: "smtp", smtp: %{relay: "smtp.example.com", port: "abc"}}
         })
         |> render_submit()
 
@@ -162,8 +138,8 @@ defmodule BerrypodWeb.Admin.EmailSettingsTest do
     end
 
     test "shows test email section when configured", %{conn: conn} do
-      Settings.put_setting("email_adapter", "postmark")
-      Settings.put_secret("email_postmark_api_key", "pm_test_abc")
+      Settings.put_setting("email_adapter", "brevo")
+      Settings.put_secret("email_brevo_api_key", "xkeysib-test-abc")
 
       {:ok, _view, html} = live(conn, ~p"/admin/settings/email")
 
@@ -182,8 +158,8 @@ defmodule BerrypodWeb.Admin.EmailSettingsTest do
     end
 
     test "sending test email shows success and sets verified flag", %{conn: conn} do
-      Settings.put_setting("email_adapter", "postmark")
-      Settings.put_secret("email_postmark_api_key", "pm_test_abc")
+      Settings.put_setting("email_adapter", "brevo")
+      Settings.put_secret("email_brevo_api_key", "xkeysib-test-abc")
 
       {:ok, view, _html} = live(conn, ~p"/admin/settings/email")
 
@@ -205,14 +181,14 @@ defmodule BerrypodWeb.Admin.EmailSettingsTest do
 
       {:ok, view, _html} = live(conn, ~p"/admin/settings/email")
 
-      # Switch to Brevo and save
+      # Switch to Brevo and save (namespaced fields)
       view
       |> form("form[phx-change=\"form_change\"]", %{email: %{adapter: "brevo"}})
       |> render_change()
 
       view
       |> form("form[phx-submit=\"save\"]", %{
-        email: %{adapter: "brevo", api_key: "xkeysib-switch-test"}
+        email: %{adapter: "brevo", brevo: %{api_key: "xkeysib-switch-test"}}
       })
       |> render_submit()
 
@@ -236,7 +212,7 @@ defmodule BerrypodWeb.Admin.EmailSettingsTest do
 
       view
       |> form("form[phx-submit=\"save\"]", %{
-        email: %{adapter: "brevo", api_key: "xkeysib-def789ghi012"}
+        email: %{adapter: "brevo", brevo: %{api_key: "xkeysib-def789ghi012"}}
       })
       |> render_submit()
 
@@ -262,13 +238,6 @@ defmodule BerrypodWeb.Admin.EmailSettingsTest do
       assert html =~ "API key"
     end
 
-    test "adapter query param preselects provider", %{conn: conn} do
-      {:ok, _view, html} = live(conn, ~p"/admin/settings/email?adapter=resend")
-
-      assert html =~ "Resend"
-      assert html =~ "API key"
-    end
-
     test "from_checklist param shows checklist banner", %{conn: conn} do
       {:ok, _view, html} = live(conn, ~p"/admin/settings/email?from=checklist")