The lint refuses a form with no action, which would have no button; portal iris names the lint

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

src/content/validate.rs

@@ -512,6 +512,20 @@ pub fn validate_questions(
     }
     for question in questions.values() {
         for alternative in &question.alternatives {
+            // A form is sent with its button, and the button is only
+            // drawn for an alternative that says where to go afterwards:
+            // without `action` the person fills it in and cannot send it.
+            let asks = alternative.features.iter().any(|f| f.requirements.iter().any(|r| r.kind != "hidden"));
+            if (asks || alternative.invite.is_some() || alternative.record_as.is_some())
+                && alternative.action.is_none()
+                && alternative.self_transition.is_none()
+            {
+                anyhow::bail!(
+                    "question {:?} alternative {:?}: it has a form to send but no `action`, so no button is drawn; give it `action:`, the page to go to once it is sent (its own page is fine)",
+                    question.id,
+                    alternative.name
+                );
+            }
             if alternative.one_per_person && alternative.record_as.is_none() {
                 anyhow::bail!(
                     "question {:?} alternative {:?}: one_per_person keeps each person's own record, and there is no record_as to keep it in",