add tests for email verification flag lifecycle

Tests that sending a test email sets the verified flag, saving config
clears it, and disconnecting clears it. Also adds unit tests for
email_verified?/mark/clear in the Mailer module.

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

test/berrypod/mailer_test.exs

@@ -59,6 +59,35 @@ defmodule Berrypod.MailerTest do
     end
   end
 
+  describe "email_verified?/0" do
+    test "returns false when adapter is Local" do
+      Application.put_env(:berrypod, Mailer, adapter: Swoosh.Adapters.Local)
+      Mailer.mark_email_verified()
+      refute Mailer.email_verified?()
+    end
+
+    test "returns false when configured but not verified" do
+      Application.put_env(:berrypod, Mailer, adapter: Swoosh.Adapters.Postmark, api_key: "test")
+      Mailer.clear_email_verified()
+      refute Mailer.email_verified?()
+    end
+
+    test "returns true when configured and verified" do
+      Application.put_env(:berrypod, Mailer, adapter: Swoosh.Adapters.Postmark, api_key: "test")
+      Mailer.mark_email_verified()
+      assert Mailer.email_verified?()
+    end
+
+    test "clear_email_verified resets the flag" do
+      Application.put_env(:berrypod, Mailer, adapter: Swoosh.Adapters.Postmark, api_key: "test")
+      Mailer.mark_email_verified()
+      assert Mailer.email_verified?()
+
+      Mailer.clear_email_verified()
+      refute Mailer.email_verified?()
+    end
+  end
+
   describe "current_config/0" do
     test "returns {nil, %{}} when no adapter configured" do
       Application.put_env(:berrypod, Mailer, adapter: Swoosh.Adapters.Local)