fix: polish attestation columns and inline grading

- use numeric semesters 1–8 and add show/hide publication per attestation
- edit attestation results directly in the group table without a modal
- hide unpublished attestations from students
- align header separators, average column and action buttons with the existing UI
- remove missed-hours fields until a separate attendance model is ready

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

@@ -28,18 +28,17 @@
     <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>
+            <tr><th>Форма аттестации</th><th>Семестр</th><th>Результат</th></tr>
             </thead>
             <tbody>
             <tr th:each="a : ${attestations}">
                 <td th:text="${a.kindLabel}">—</td>
-                <td th:text="${a.semester}">—</td>
+                <td th:text="'Семестр ' + ${a.semester}">—</td>
                 <td>
                     <span class="badge"
                           th:classappend="${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>