fix: version badge rendering, Jinja2 scoping, navbar i18n, missing GET task endpoint

- Fix version badge showing [object Object] or Python dict dump in
  select_recipe, task_list, and task_complete templates by accessing
  current_version.version_number instead of the whole object
- Fix recipe_editor.html Internal Server Error caused by Jinja2 block
  scoping: {% set %} variables from block content were invisible in
  block extra_js, replaced with direct recipe.* references
- Fix task_editor.html SyntaxError from Italian apostrophe in
  nell'eliminazione breaking JS string literals, switched to |tojson
- Add i18n {{ _() }} wrappers to all hardcoded navbar strings (desktop
  and mobile menus) so language toggle works correctly
- Add app title text "TieMeasureFlow" next to logo in navbar
- Add missing GET /api/tasks/{task_id} endpoint on server that caused
  405 Method Not Allowed when starting measurements

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

client/templates/maker/task_editor.html

@@ -1227,7 +1227,7 @@ function taskEditor() {
           this.successMessage = '{{ _("Task eliminato") }}';
         } else {
           const data = await resp.json();
-          this.errorMessage = data.detail || '{{ _("Errore nell\'eliminazione del task") }}';
+          this.errorMessage = data.detail || {{ _("Errore nell'eliminazione del task")|tojson }};
         }
       } catch (err) {
         console.error('deleteTask error:', err);
@@ -1510,7 +1510,7 @@ function taskEditor() {
           this.successMessage = '{{ _("Misurazione eliminata") }}';
         } else {
           const data = await resp.json();
-          this.errorMessage = data.detail || '{{ _("Errore nell\'eliminazione della misurazione") }}';
+          this.errorMessage = data.detail || {{ _("Errore nell'eliminazione della misurazione")|tojson }};
         }
       } catch (err) {
         console.error('deleteSubtask error:', err);