Lab editing and group grades

- academic-service: PUT /labs/{id} (title, deadline, defense, points, status,
  description), POST/PUT/DELETE variants endpoints
- progress-service: lab_grades table, POST/GET /api/v1/grades, GET /me/grades
- gateway: routes for /api/v1/assign and /api/v1/grades
- web: lab edit page (metadata + per-variant forms + add/delete variant)
- web: group page shows grades matrix per lab with editable score inputs
  and computed average column
- web: student dashboard renders statement via markdown, shows deadline

web/src/main/resources/static/css/app.css

@@ -163,6 +163,7 @@ tr:last-child td { border-bottom: none; }
 .inline-form { display: inline-flex; align-items: center; gap: 0.375rem; margin: 0; }
 .inline-form .input-sm { width: auto; min-width: 10rem; }
 .input-sm { padding: 0.25rem 0.5rem; font-size: 0.8125rem; }
+.input-score { width: 4.5rem; }
 .filter-select { width: auto; }
 .hidden { display: none !important; }