fix email settings: missing providers, a11y, no-JS support

show all 10 providers in three groups (popular, transactional,
advanced) with category headings. fix phx-change clobbering text
fields, async test email sending state, integer parse crash on
bad port. add keyboard focus on card radios, fieldset legend,
WCAG-compliant badge contrast, responsive grid. extract shared
save_config into Mailer, add no-JS controller fallback with
configured_adapter hidden field for adapter change detection.
remove CardRadioScroll JS hook (no longer needed).

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

lib/berrypod/mailer.ex

@@ -1,6 +1,7 @@
 defmodule Berrypod.Mailer do
   use Swoosh.Mailer, otp_app: :berrypod
 
+  alias Berrypod.KeyValidation
   alias Berrypod.Mailer.Adapters
   alias Berrypod.Settings
 
@@ -132,6 +133,117 @@ defmodule Berrypod.Mailer do
     Settings.get_setting("email_from_address") || "noreply@#{default_from_domain()}"
   end
 
+  @doc """
+  Validates and persists email adapter configuration.
+
+  Trims values, validates required fields and key formats, clears settings
+  from other providers, and applies config immediately.
+
+  Returns `{:ok, adapter_info}` on success or `{:error, field_errors}`
+  where field_errors is a map of field_key => error_message.
+  """
+  def save_config(adapter_key, params, fallback_from_email) do
+    case Adapters.get(adapter_key) do
+      nil ->
+        {:error, %{"_base" => "Please select an email provider"}}
+
+      adapter_info ->
+        params = trim_params(params)
+        field_errors = validate_adapter_fields(adapter_info, params)
+
+        if field_errors == %{} do
+          persist_adapter_config(adapter_info, params, fallback_from_email)
+          {:ok, adapter_info}
+        else
+          {:error, field_errors}
+        end
+    end
+  end
+
+  defp trim_params(params) do
+    Map.new(params, fn {k, v} -> {k, if(is_binary(v), do: String.trim(v), else: v)} end)
+  end
+
+  defp validate_adapter_fields(adapter_info, params) do
+    missing_errors =
+      for field <- adapter_info.fields,
+          field.required,
+          val = params[field.key],
+          is_nil(val) or val == "",
+          # Secret fields can be left blank to keep existing value
+          not (field.type == :secret and
+                 Settings.get_secret(Adapters.settings_key(adapter_info.key, field.key)) != nil),
+          into: %{} do
+        {field.key, "#{field.label} is required"}
+      end
+
+    format_errors =
+      for field <- adapter_info.fields,
+          field.type == :secret,
+          value = params[field.key],
+          value != nil and value != "",
+          {:error, message} <- [
+            KeyValidation.validate_email_key(value, adapter_info.key, field.key)
+          ],
+          into: %{} do
+        {field.key, message}
+      end
+
+    integer_errors =
+      for field <- adapter_info.fields,
+          field.type == :integer,
+          value = params[field.key],
+          is_binary(value) and value != "",
+          match?(:error, Integer.parse(value)),
+          into: %{} do
+        {field.key, "#{field.label} must be a number"}
+      end
+
+    missing_errors |> Map.merge(format_errors) |> Map.merge(integer_errors)
+  end
+
+  defp persist_adapter_config(adapter_info, params, fallback_from_email) do
+    # Clear settings from other providers
+    new_keys = MapSet.new(Adapters.field_keys(adapter_info))
+
+    for key <- Adapters.all_field_keys(), key not in new_keys do
+      Settings.delete_setting(key)
+    end
+
+    # Save adapter type
+    Settings.put_setting("email_adapter", adapter_info.key)
+
+    # Save field values (blank secrets keep existing value)
+    for field <- adapter_info.fields do
+      value = params[field.key]
+      settings_key = Adapters.settings_key(adapter_info.key, field.key)
+
+      cond do
+        value && value != "" ->
+          case field.type do
+            :secret -> Settings.put_secret(settings_key, value)
+            :integer -> Settings.put_setting(settings_key, String.to_integer(value), "integer")
+            _ -> Settings.put_setting(settings_key, value)
+          end
+
+        field.type == :secret ->
+          :keep
+
+        true ->
+          Settings.delete_setting(settings_key)
+      end
+    end
+
+    # Auto-set from address to admin email if not configured
+    if Settings.get_setting("email_from_address") in [nil, ""] do
+      Settings.put_setting("email_from_address", fallback_from_email)
+    end
+
+    # Require re-verification and apply immediately
+    clear_email_verified()
+    load_config()
+  end
+
   @doc """
   Turns a raw delivery error into a user-friendly message.