Refactor UI assets and harden quality checks

tests/test_layout.py

@@ -0,0 +1,46 @@
+from karldns.web.html_utils import trusted
+from karldns.web.layout import PageOptions, _page, _social_meta_tags, _structured_data_tag
+
+
+def test_page_options_render_metadata_and_preloads() -> None:
+    html = _page(
+        "KarlDNS",
+        trusted("<main id='main'></main>"),
+        PageOptions(
+            description="Dynamic DNS",
+            preload_logo=True,
+            canonical_url="https://karldns.example/",
+            image_url="https://karldns.example/social.png",
+            image_alt="Preview",
+            structured_data={"name": "KarlDNS"},
+        ),
+    )
+
+    assert 'content="Dynamic DNS"' in html
+    assert 'rel="canonical" href="https://karldns.example/"' in html
+    assert 'rel="preload" as="image" href="/logo.webp?v=3"' in html
+    assert 'property="og:image" content="https://karldns.example/social.png"' in html
+    assert 'type="application/ld+json"' in html
+
+
+def test_social_meta_tags_include_large_card_when_image_exists() -> None:
+    html = _social_meta_tags(
+        title="KarlDNS",
+        description="Dynamic DNS",
+        canonical_url="https://karldns.de/",
+        image_url="https://karldns.de/social-preview.png",
+        image_alt="Preview",
+    )
+
+    assert 'property="og:title" content="KarlDNS"' in html
+    assert 'property="og:image" content="https://karldns.de/social-preview.png"' in html
+    assert 'name="twitter:card" content="summary_large_image"' in html
+    assert 'name="twitter:image:alt" content="Preview"' in html
+
+
+def test_structured_data_tag_escapes_json_for_html() -> None:
+    html = _structured_data_tag({"name": "KarlDNS", "description": "<dynamic>"})
+
+    assert 'type="application/ld+json"' in html
+    assert "&lt;dynamic&gt;" in html
+    assert "<dynamic>" not in html