sync: bring Rust crates in line with nuwiki main (v0.4.2)

crates/nuwiki-core/tests/html_renderer.rs

@@ -77,6 +77,27 @@ fn centered_heading_gets_centered_class() {
     assert!(out.contains("<h1 class=\"centered\" id=\"T\">T</h1>"));
 }
 
+#[test]
+fn spaceless_heading_renders_as_heading() {
+    // `==Heading==` (no surrounding spaces) is a heading, like vimwiki — not a
+    // literal `<p>==Heading==</p>`.
+    let out = render("==Plain==\n");
+    assert!(
+        out.contains(
+            "<div id=\"Plain\"><h2 id=\"Plain\" class=\"header\">\
+             <a href=\"#Plain\">Plain</a></h2></div>"
+        ),
+        "got: {out}"
+    );
+    // The spaceless + keyword combo from the report: a header, not a badge.
+    let out2 = render("==TODO==\n");
+    assert!(
+        out2.contains("<h2 id=\"TODO\" class=\"header\">"),
+        "got: {out2}"
+    );
+    assert!(!out2.contains("<p>"), "not a paragraph: {out2}");
+}
+
 #[test]
 fn heading_keyword_renders_as_plain_text_not_badge() {
     // `== TODO ==` is a section title, not an inline keyword: it must render as