Question nav + gateway alternatives

- QuestionNav: every other question the visitor currently qualifies
  for, rendered under each page's alternatives - a concern reaches
  the people it speaks to without claiming front-page space, and an
  owner sees the gated desks in the same nav. Context-dependent by
  session (list_qualifying_questions filters via is_qualified).
- An alternative with an action but nothing to submit, confirm, or
  record is a gateway: its button now renders as a real link instead
  of a form submit that did nothing.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/app.rs

@@ -196,19 +196,23 @@ fn QuestionView(
                     }
                 }
                 key=|a| a.name.clone()
-                children=move |alt: Alternative| {
-                    view! {
-                        <AlternativeCard
-                            question_id=question_id.clone()
-                            alternative=alt
-                            parent_hash=parent_hash.clone()
-                            query_email=query_email.clone()
-                        />
+                children={
+                    let question_id = question_id.clone();
+                    move |alt: Alternative| {
+                        view! {
+                            <AlternativeCard
+                                question_id=question_id.clone()
+                                alternative=alt
+                                parent_hash=parent_hash.clone()
+                                query_email=query_email.clone()
+                            />
+                        }
+                        .into_any()
                     }
-                    .into_any()
                 }
             />
         </div>
+        <QuestionNav current_id=question_id/>
         {question
             .responsible
             .clone()
@@ -219,6 +223,39 @@ fn QuestionView(
     .into_any()
 }
 
+/// Every other question the visitor currently qualifies for, as a
+/// small nav - how a concern reaches the people it speaks to without
+/// claiming front-page space (an owner also sees the gated desks here).
+#[component]
+fn QuestionNav(current_id: String) -> impl IntoView {
+    let nav = Resource::new(|| (), |_| list_qualifying_questions());
+    view! {
+        <Suspense fallback=|| ()>
+            {move || {
+                let current_id = current_id.clone();
+                nav.get().and_then(|res| res.ok()).map(|items| {
+                    let others: Vec<(String, String)> = items
+                        .into_iter()
+                        .filter(|(id, _)| *id != current_id)
+                        .collect();
+                    (!others.is_empty()).then(|| view! {
+                        <nav class="question-nav">
+                            <span class="question-nav-lead">"Also worth asking"</span>
+                            <For
+                                each=move || others.clone()
+                                key=|(id, _)| id.clone()
+                                children=|(id, name): (String, String)| {
+                                    view! { <a href=id>{name}</a> }.into_any()
+                                }
+                            />
+                        </nav>
+                    })
+                })
+            }}
+        </Suspense>
+    }
+}
+
 /// "Asked by X — contact them if you get stuck."
 /// The mailto address is assembled from `data-user`/`data-domain` on a
 /// real mouse event, never baked into the server-rendered `href` -
@@ -463,6 +500,16 @@ fn AlternativeCard(
 
     let has_action = alternative.action.is_some();
     let has_requirements = alternative.features.iter().any(|f| !f.requirements.is_empty());
+    // Nothing to submit, nothing to confirm, nothing to record: the
+    // alternative is a gateway to another question, and its button is
+    // just a link (a form submit would be a click that does nothing).
+    let is_gateway = has_action
+        && !has_requirements
+        && alternative.record_as.is_none()
+        && alternative
+            .features
+            .iter()
+            .all(|f| f.resource.as_ref().is_none_or(|r| r.transitions.is_empty()));
 
     // Shared across every resource feature on this alternative: which
     // row(s) have a transition selected but not yet confirmed, keyed by
@@ -841,19 +888,30 @@ fn AlternativeCard(
                                     children=move |e| view! { <p class="alt-encouragement">{e}</p> }
                                 />
                             </div>
-                            <form on:submit=on_submit>
-                                <button
-                                    type="submit"
-                                    class="alt-submit"
-                                    disabled=move || {
-                                        (!has_requirements && pending_transitions.get().is_empty())
-                                            || submit.pending().get()
-                                            || transition_batch.pending().get()
-                                    }
-                                >
-                                    {button_label.clone()}
-                                </button>
-                            </form>
+                            {if is_gateway {
+                                let href = alternative.action.clone().unwrap_or_default();
+                                view! {
+                                    <a class="alt-submit" href=href>{button_label.clone()}</a>
+                                }
+                                .into_any()
+                            } else {
+                                view! {
+                                    <form on:submit=on_submit>
+                                        <button
+                                            type="submit"
+                                            class="alt-submit"
+                                            disabled=move || {
+                                                (!has_requirements && pending_transitions.get().is_empty())
+                                                    || submit.pending().get()
+                                                    || transition_batch.pending().get()
+                                            }
+                                        >
+                                            {button_label.clone()}
+                                        </button>
+                                    </form>
+                                }
+                                .into_any()
+                            }}
                         </div>
                     }
                 })}
@@ -1372,6 +1430,33 @@ pub async fn get_question(path: String) -> Result<Option<Question>, ServerFnErro
     Ok(state.questions.load().get(&path).cloned())
 }
 
+/// Every question the current visitor qualifies for, as (id, name) -
+/// the site nav's data. Context-dependent: an owner session sees the
+/// gated pages too, an anonymous visitor only the public ones.
+#[server]
+pub async fn list_qualifying_questions() -> Result<Vec<(String, String)>, ServerFnError> {
+    use crate::auth::{User, SESSION_USER_KEY};
+    use crate::content::is_qualified;
+    use crate::server::AppState;
+
+    let state = expect_context::<AppState>();
+    let session: tower_sessions::Session = leptos_axum::extract().await?;
+    let user = session
+        .get::<User>(SESSION_USER_KEY)
+        .await
+        .map_err(|e| ServerFnError::new(e.to_string()))?;
+
+    let mut out: Vec<(String, String)> = state
+        .questions
+        .load()
+        .values()
+        .filter(|q| is_qualified(user.as_ref(), q))
+        .map(|q| (q.id.clone(), q.name.clone()))
+        .collect();
+    out.sort();
+    Ok(out)
+}
+
 #[derive(Clone, Debug, Serialize, Deserialize)]
 pub struct SubmitResult {
     pub next: Option<String>,