An invite may carry its own mail, with the form's fields and a spoken date and time

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GT37Z1Xtfd9pUuQtMTg6Yt

src/content/mod.rs

@@ -391,6 +391,13 @@ pub struct Alternative {
 #[derive(Clone, Debug, Serialize, Deserialize)]
 pub struct Invite {
     pub group: String,
+    /// This invite's own mail, in place of the site's (`mail.invite`):
+    /// an invitation to a conversation at an hour, say. Besides
+    /// `{name}`, `{link}`, `{expires}`, `{username}`, `{group}`,
+    /// `{site}` and `{site_name}`, every field of the form is a
+    /// placeholder; a date and time is written out in words.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub mail: Option<MailTemplate>,
 }
 
 #[derive(Clone, Debug, Serialize, Deserialize)]