Fix ValueError in audiencia form and AttributeError on HEAD requests

- audiencia/forms.py: also catch ValueError when querying MateriaLegislativa
  by numero, so a non-numeric input (e.g. '36  e 61') surfaces as a form
  validation error instead of an unhandled 500.
- utils.py: MultiFormatOutputMixin.render_to_response was doing
  getattr(request, request.method) which fails for HEAD requests because
  Django exposes request.GET/POST but not request.HEAD; remap HEAD → GET.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

sapl/audiencia/forms.py

@@ -115,7 +115,7 @@ class AudienciaForm(FileFieldCheckMixin, forms.ModelForm):
                     numero=materia,
                     ano=ano_materia,
                     tipo=tipo_materia)
-            except ObjectDoesNotExist:
+            except (ObjectDoesNotExist, ValueError):
                 msg = _('A matéria %s nº %s/%s não existe no cadastro'
                         ' de matérias legislativas.' % (tipo_materia, materia, ano_materia))
                 self.logger.warning(

sapl/utils.py

@@ -1395,8 +1395,9 @@ class MultiFormatOutputMixin:
         return {fmt: fields for fmt in self.formats_impl}
 
     def render_to_response(self, context, **response_kwargs):
-        format_result = getattr(self.request, self.request.method).get(
+        # HEAD shares query params with GET; Django has no request.HEAD attribute.
-            'format', None)
+        _method = 'GET' if self.request.method == 'HEAD' else self.request.method
+        format_result = getattr(self.request, _method).get('format', None)
 
         if format_result:
             if format_result not in self.formats_impl: