Use canonical production domain.

Reference https://www.askaplumberfirst.com for production email links and configuration examples.

.env.example

@@ -18,7 +18,7 @@ SECURE_COOKIE=0
 # RESEND_API_KEY=re_xxxxxxxxx
 # RESEND_FROM=Ask a Plumber <notify@yourdomain.com>
 # Public site origin used in email links (required when Resend is enabled):
-# APP_BASE_URL=https://askaplumber.example
+# APP_BASE_URL=https://www.askaplumberfirst.com
 # DigitalOcean Spaces (profile avatars). Leave unset to disable uploads.
 # SPACES_KEY=
 # SPACES_SECRET=

internal/mail/mail_test.go

@@ -17,7 +17,7 @@ func TestEmbeddedMarkIsPNG(t *testing.T) {
 func TestPostReplyContent(t *testing.T) {
 	t.Parallel()
 
-	text, htmlBody := postReplyContent("https://plumber.example/", PostReply{
+	text, htmlBody := postReplyContent("https://www.askaplumberfirst.com/", PostReply{
 		ToName:          `<Sam & Pat>`,
 		RootID:          "question-123",
 		RootTitle:       `<b>Leaky sink</b>`,
@@ -30,7 +30,7 @@ func TestPostReplyContent(t *testing.T) {
 		"Ask a Plumber First",
 		"New reply",
 		"cid:reply-notification-mark",
-		"https://plumber.example/questions/question-123#post-reply-456",
+		"https://www.askaplumberfirst.com/questions/question-123#post-reply-456",
 		"white-space:pre-wrap",
 		"&lt;Sam &amp; Pat&gt;",
 		"&lt;b&gt;Leaky sink&lt;/b&gt;",
@@ -58,7 +58,7 @@ func TestPostReplyContent(t *testing.T) {
 		`Hi <Sam & Pat>,`,
 		`<Jo & Co> replied in "<b>Leaky sink</b>"`,
 		"Replace the cartridge.\nThen test the handle.",
-		"https://plumber.example/questions/question-123#post-reply-456",
+		"https://www.askaplumberfirst.com/questions/question-123#post-reply-456",
 	} {
 		if !strings.Contains(text, want) {
 			t.Errorf("text missing %q", want)
@@ -69,7 +69,7 @@ func TestPostReplyContent(t *testing.T) {
 func TestPostReplyContentUsesFallbacks(t *testing.T) {
 	t.Parallel()
 
-	text, htmlBody := postReplyContent("https://plumber.example", PostReply{})
+	text, htmlBody := postReplyContent("https://www.askaplumberfirst.com", PostReply{})
 	if !strings.Contains(text, `Someone replied in "your conversation"`) {
 		t.Errorf("text missing fallback title")
 	}