test(lsp): update find_section_range test for any-level heading match

The prior commit (e849ac9) intentionally removed the h1-only
restriction from find_section_range so VimwikiGenerateTagLinks stays
idempotent under non-h1 tag headings. The accompanying test still
asserted the old h1-only behavior and now fails.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

crates/nuwiki-lsp/tests/link_health.rs

@@ -343,11 +343,13 @@ fn find_section_range_misses_when_absent() {
 }
 
 #[test]
-fn find_section_range_only_matches_h1() {
+fn find_section_range_matches_any_heading_level() {
+    // Section replacement accepts any heading level so
+    // VimwikiGenerateTagLinks stays idempotent when tag sections live
+    // under non-h1 headings (e.g. `== Tag: foo ==`).
     let src = "== Contents ==\n- [[A]]\n";
     let ast = parse(src);
-    // h2 — should not match.
-    assert!(ops::find_section_range(&ast, "Contents").is_none());
+    assert!(ops::find_section_range(&ast, "Contents").is_some());
 }
 
 // ===== toc_edit =====