test(v0): render page swap content from hemplate

Exercise the v0 page-swap effect with a renderable hemplate view payload instead of an ad hoc HTML-looking text literal.

req: view/001

req: html_safety/002

req: page_swap/002

req: page_swap/003

examples/v0/src/lib.rs

@@ -36,6 +36,12 @@ mod tests {
         title: String,
     }
 
+    #[derive(Hemplate)]
+    #[hemplate = "partials"]
+    struct DocsContent {
+        message: &'static str,
+    }
+
     // req: examples/001 req: ceremony/001 req: build/001 req: build/005 req: codegen/002
     #[test]
     fn counter_updates_a_generated_slot() {
@@ -85,12 +91,12 @@ mod tests {
         assert!(matches!(effect.ops(), [Effect::Put { .. }]));
     }
 
-    // req: examples/001 req: page_swap/002 req: page_swap/003 req: build/001 req: build/005
+    // req: examples/001 req: page_swap/002 req: page_swap/003 req: build/001 req: build/005 req: view/001
     #[test]
     fn page_swap_updates_content_and_history() {
         fn load_docs() -> impl IntoEffect {
             (
-                ui::slots::content.text("<h1>Docs</h1>"),
+                ui::slots::content.html(render_docs_content("This page was swapped.")),
                 ui::slots::title.text("Docs"),
                 push("/docs"),
             )
@@ -100,9 +106,19 @@ mod tests {
 
         assert!(effect.has_slot(ui::slots::content));
         assert!(effect.has_slot(ui::slots::title));
+        assert!(matches!(effect.ops().first(), Some(Effect::Put { payload: Payload::Html(_), .. })));
         assert!(matches!(effect.ops().last(), Some(Effect::Navigate { url, mode: NavigateMode::Push, .. }) if url == "/docs"));
     }
 
+    fn render_docs_content(message: &'static str) -> SafeHtml {
+        // req: html_safety/002 req: view/001
+        SafeHtml::trusted(
+            DocsContent { message }
+                .render()
+                .expect("v0 docs content renders"),
+        )
+    }
+
     // req: examples/001 req: progressive_disclosure/001 req: build/001 req: build/005 req: codegen/004
     #[test]
     fn auth_flow_reads_typed_input_and_updates_status() {