test(examples): assert escaped text exactly

Make v0 and kanban DOM-aware escaped-text checks exact instead of substring-based while preserving the no-rendered-tag assertions.

req: html_safety/002

req: test/005

examples/v0/src/main.rs

@@ -301,7 +301,7 @@ mod tests {
         let rows = document.select(&selector("li[data-key]")).collect::<Vec<_>>();
         assert_eq!(rows.len(), 1);
         assert_eq!(rows[0].value().attr("data-key"), Some("7"));
-        assert!(rows[0].text().collect::<String>().contains("<b>Ship v0</b>"));
+        assert_eq!(rows[0].text().collect::<String>(), "<b>Ship v0</b>");
         assert!(document.select(&selector("b")).next().is_none());
     }