Remove unused templates for newsletter creation, settings, and submissions; update unsubscribe confirmation link; add tests for email templates API.

templates/admin/admin_newsletter.html

@@ -0,0 +1,42 @@
+{% extends "_base.html" %} {% block title %}Newsletter Subscribers{% endblock %}
+{% block heading %}Newsletter Subscribers{% endblock %} {% block extra_styles %}
+<link rel="stylesheet" href="/static/css/admin.css" /> {% endblock %} {% block
+content %}
+
+<div id="message"></div>
+
+<div class="filters">
+  <input type="text" id="emailFilter" placeholder="Filter by email..." />
+  <select id="sortBy">
+    <option value="subscribed_at">Sort by Date</option>
+    <option value="email">Sort by Email</option>
+  </select>
+  <select id="sortOrder">
+    <option value="desc">Newest First</option>
+    <option value="asc">Oldest First</option>
+  </select>
+  <button onclick="applyFilters()">Apply Filters</button>
+  <button onclick="clearFilters()">Clear</button>
+</div>
+
+<div id="loading" class="loading">Loading subscribers...</div>
+<table id="subscribersTable" class="subscribers-table" style="display: none">
+  <thead>
+    <tr>
+      <th>Email</th>
+      <th>Subscribed Date</th>
+      <th>Actions</th>
+    </tr>
+  </thead>
+  <tbody id="subscribersBody"></tbody>
+</table>
+
+<div id="pagination" class="pagination" style="display: none">
+  <button id="prevBtn" onclick="changePage(currentPage - 1)">Previous</button>
+  <span id="pageInfo"></span>
+  <button id="nextBtn" onclick="changePage(currentPage + 1)">Next</button>
+</div>
+
+{% endblock %} {% block extra_scripts %}
+<script src="/static/js/admin.js"></script>
+{% endblock %}