Ajoute une largeur maximale optionnelle aux blocs de texte (titre/paragraphe)

Nouvel attribut max_width (vide par défaut = pleine largeur, inchangé)
sur les kinds titre/paragraphe, réglable depuis leur panneau
Propriétés. Le sous-titre de la page de garde du thème Sécurité
Incendie l'utilise (60ch) pour rester conforme à la maquette d'origine,
qui ne l'étirait pas sur toute la largeur de la page.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

tests/document/test_document_elements.py

@@ -400,3 +400,36 @@ def test_bouton_with_attachment_filename_renders_data_attribute(tmp_support_slug
 
     html = doc_engine.render_document(doc_engine.list_document_elements(slug, page_id))
     assert 'data-attachment-filename="fiche-consignes.pdf"' in html
+
+
+def test_paragraphe_default_max_width_is_empty(tmp_support_slug_cleanup: Any) -> None:
+    slug, page_id = _new_support(tmp_support_slug_cleanup)
+    element_id = doc_engine.add_document_element(slug, "paragraphe", page_id=page_id)
+    element = doc_engine.get_document_element(slug, element_id)
+    assert element is not None
+    assert element["attributes"]["max_width"] == ""
+
+    html = doc_engine.render_document(doc_engine.list_document_elements(slug, page_id))
+    assert "max-width" not in html
+
+
+def test_paragraphe_with_max_width_adds_it_to_the_inline_style(tmp_support_slug_cleanup: Any) -> None:
+    slug, page_id = _new_support(tmp_support_slug_cleanup)
+    element_id = doc_engine.add_document_element(slug, "paragraphe", page_id=page_id)
+    doc_engine.update_document_element_attributes(
+        slug, element_id, {"content": "Texte", "style": "paragraphe", "max_width": "60ch"}
+    )
+
+    html = doc_engine.render_document(doc_engine.list_document_elements(slug, page_id))
+    assert "max-width:60ch;" in html
+
+
+def test_paragraphe_max_width_is_escaped(tmp_support_slug_cleanup: Any) -> None:
+    slug, page_id = _new_support(tmp_support_slug_cleanup)
+    element_id = doc_engine.add_document_element(slug, "paragraphe", page_id=page_id)
+    doc_engine.update_document_element_attributes(
+        slug, element_id, {"content": "Texte", "style": "paragraphe", "max_width": '"><script>alert(1)</script>'}
+    )
+
+    html = doc_engine.render_document(doc_engine.list_document_elements(slug, page_id))
+    assert "<script>" not in html

tests/document/test_document_themes.py

@@ -32,6 +32,17 @@ def test_securite_incendie_title_page_is_vertically_centered() -> None:
     assert entry["seed_pages"][1].get("vertical_align", "top") == "top"
 
 
+def test_securite_incendie_intro_paragraph_has_a_max_width() -> None:
+    """Retour utilisateur du 24/09/2026 : le sous-titre de la page de
+    garde doit rester aussi étroit que dans la maquette, pas étiré sur
+    toute la largeur de la page."""
+    entry = doc_engine.get_document_theme_entry("securite-incendie")
+    assert entry is not None
+    intro_paragraph = entry["seed_pages"][0]["blocks"][2]
+    assert intro_paragraph["kind"] == "paragraphe"
+    assert intro_paragraph["attributes"]["max_width"] == "60ch"
+
+
 def test_seed_blocks_to_elements_assigns_unique_synthetic_ids() -> None:
     blocks: list[dict[str, Any]] = [
         {"kind": "titre", "attributes": {"content": "Titre"}},