fix: doppelte Tabellen-Anker und Bild-Links im Linkcheck

- Komplexe Tabellen mit verlinkter id erzeugten den Anker zweimal
  (<a id> und <table id>), also ungültiges HTML.
- Der Linkcheck übersah das äußere Ziel von Bild-Links
  [![alt](img)](ziel) und startete Links an escapten \[-Klammern.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/test_links.py

@@ -66,3 +66,18 @@ def test_link_checker_detects_problems():
     }
     broken = check_links(files, {"media/images/a.png"})
     assert {b["link"] for b in broken} == {"002-b.md#nein", "003.md"}
+
+
+def test_link_checker_ignores_escaped_brackets():
+    """An escaped \\[ must not start a link that swallows the following paragraphs."""
+    files = {
+        "a.md": '\\[»\\] Hinweis\n\n<a id="x"></a>Text [kaputt](fehlt.md) und \\[1\\]\n\n[ok](#x)\n',
+    }
+    broken = check_links(files, set())
+    assert [b["link"] for b in broken] == ["fehlt.md"]
+
+
+def test_link_checker_handles_image_links():
+    files = {"a.md": "[![Abb.](bild.png)](fehlt.md) [![ok](bild.png)](#x) <a id=\"x\"></a>\n"}
+    broken = check_links(files, {"bild.png"})
+    assert [b["link"] for b in broken] == ["fehlt.md"]

tests/test_tables_lists.py

@@ -63,3 +63,10 @@ def test_unknown_elements_are_reported_and_keep_html(convert):
     kept = convert(Book(docs=[Doc("c.xhtml", body)]), "--keep-html")
     assert '<foo-widget data-x="1">Inhalt bleibt</foo-widget>' in kept.chapter("001")
     assert "evil" not in kept.chapter("001")
+
+
+def test_complex_table_anchor_is_emitted_once(convert):
+    body = ('<h1>T</h1><p><a href="#t1">Tabelle 1</a></p><table id="t1"><tr><td colspan="2">a</td></tr>'
+            "<tr><td>b</td><td>c</td></tr></table>")
+    text = convert(Book(docs=[Doc("c.xhtml", body)])).chapter("001")
+    assert text.count('id="t1"') == 1