fix(feedback): inline edit + live status change without reload

- Replaced broken status_aendern (missing status_choices in response)
  with a single eintrag_bearbeiten view that always returns the full
  partial context
- eintrag_zeile.html is now a <tbody x-data="{ editing: false }"> with
  two rows: display row + collapsible edit form
- Click anywhere on a row to expand the edit form; @click.stop on the
  status cell prevents accidental toggles
- Status dropdown in the display row posts via HTMX and swaps the whole
  <tbody> — no page reload needed
- Edit form covers all fields: titel, beschreibung, kategorie,
  dringlichkeit, status, bewertung, entscheidung

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

vergabe_teilnahme/apps/feedback/urls.py

@@ -8,5 +8,5 @@ urlpatterns = [
     path('modal/', views.modal, name='modal'),
     path('', views.submit, name='submit'),
     path('backlog/', views.backlog, name='backlog'),
-    path('backlog/<int:pk>/status/', views.status_aendern, name='status_aendern'),
+    path('backlog/<int:pk>/bearbeiten/', views.eintrag_bearbeiten, name='eintrag_bearbeiten'),
 ]