feat: add course attestations and average grade column

- store attestation columns and per-student results in progress-service
- add teacher UI for intermediate/pass/exam columns with semester and missed hours
- show average score per student on the group page
- show attestation results on the student dashboard

web/src/main/resources/templates/student/dashboard.html

@@ -24,6 +24,30 @@
         <a class="btn btn-secondary" th:href="@{/learn}">Учебные материалы</a>
     </div>
 
+    <h2 class="section-title mt-8">Аттестации</h2>
+    <div th:if="${!#lists.isEmpty(attestations)}" class="card card-flush mb-6">
+        <table>
+            <thead>
+            <tr><th>Форма аттестации</th><th>Семестр</th><th>Результат</th><th>Пропущено</th></tr>
+            </thead>
+            <tbody>
+            <tr th:each="a : ${attestations}">
+                <td th:text="${a.kindLabel}">—</td>
+                <td th:text="${a.semester}">—</td>
+                <td>
+                    <span class="badge"
+                          th:classappend="${a.positive == true} ? 'badge-ok' : (${a.positive == false} ? 'badge-warn' : '')"
+                          th:text="${a.valueLabel}">—</span>
+                </td>
+                <td class="text-muted" th:text="${a.missedHours != null ? a.missedHours + ' ч.' : '—'}">—</td>
+            </tr>
+            </tbody>
+        </table>
+    </div>
+    <div th:if="${#lists.isEmpty(attestations)}" class="card card-body text-muted mb-6">
+        Аттестаций пока нет. Преподаватель добавит результаты после их выставления.
+    </div>
+
     <h2 class="section-title mt-8">Мои лабораторные</h2>
     <div class="row row-cols-1 row-cols-lg-2 g-4">
         <div th:each="c : ${cards}" class="col"><div class="card h-100">