Complete distribution flow and student UI

- progress-service: Distribute variants (round-robin per lab per level),
  student level assignment, API for levels/assignments
- progress-service: Inter-service clients (academic, identity) via RestClient
- web: Admin lab detail page with distribute/level buttons
- web: Student dashboard shows assigned labs from progress-service
- web: ApiClient methods for labs detail, distribute, levels, me/assignments
- academic-service: Add id to LabLevelDetail DTO for progress-service
- Fix: CSS-only layout, footer at bottom via flex column

web/src/main/resources/templates/admin/lab.html

@@ -0,0 +1,43 @@
+<!DOCTYPE html>
+<html lang="ru" xmlns:th="http://www.thymeleaf.org" th:replace="~{fragments/base :: layout(~{::title}, ~{::#content})}">
+<head><title th:text="${lab.title} + ' — LMS'">Лабораторная</title></head>
+<body>
+<div id="content">
+    <a th:href="@{/admin/labs}" class="text-sm">← Все лабораторные</a>
+    <div class="mt-4 mb-6 flex flex-wrap items-center justify-between gap-4">
+        <div><h1 class="page-title" th:text="|${lab.number}. ${lab.title}|">ЛР 1</h1><p class="text-sm text-muted">Статус: <span class="badge" th:classappend="${lab.status == 'published'} ? 'badge-ok' : 'badge-warn'" th:text="${lab.status}">—</span></p></div>
+        <form th:action="@{/admin/labs/{id}/distribute(id=${lab.id})}" method="post">
+            <button class="btn btn-primary" type="submit" name="force" value="false">Распределить</button>
+            <button class="btn btn-secondary" type="submit" name="force" value="true">Перераспределить (сбросить ручные)</button>
+        </form>
+    </div>
+    <div th:if="${notice}" class="alert alert-success" th:text="${notice}"></div>
+    <div th:if="${error}" class="alert alert-error" th:text="${error}"></div>
+
+    <h2 class="section-title">Уровни вариантов</h2>
+    <div class="card card-flush mt-2 mb-6">
+        <table>
+            <thead><tr><th>Код</th><th>Название</th><th>Вариантов</th></tr></thead>
+            <tbody>
+            <tr th:each="level : ${lab.levels}">
+                <td th:text="${level.code}">—</td>
+                <td th:text="${level.title}">—</td>
+                <td th:text="${#lists.size(level.variants)}">0</td>
+            </tr>
+            </tbody>
+        </table>
+    </div>
+
+    <h2 class="section-title">Студенты и варианты</h2>
+    <p class="text-sm text-muted mb-4">Нажмите «Распределить», чтобы закрепить варианты. Можно задать уровень студента.</p>
+    <div class="card card-flush">
+        <table>
+            <thead><tr><th>Студент</th><th>Уровень</th><th>Вариант</th></tr></thead>
+            <tbody id="student-rows">
+            <!-- Filled dynamically after distribution -->
+            </tbody>
+        </table>
+    </div>
+</div>
+</body>
+</html>