feat: add chat log admin management and refactor admin panel to lazy-load tab content

frontend/admin/schedule.html

@@ -0,0 +1,26 @@
+<div class="panel-header-row">
+    <div>
+        <h1>Schedule</h1>
+        <p>Read-only view of the currently configured playout order.</p>
+    </div>
+    <button id="reload-schedule-btn" type="button" class="btn btn-secondary">Reload schedule</button>
+</div>
+
+<div class="panel-card">
+    <p class="small-muted"><span id="schedule-matched-entries">0</span>/<span id="schedule-total-entries">0</span> matched • total runtime <span id="schedule-total-runtime">00:00:00</span></p>
+    <div class="table-wrap">
+        <table class="data-table">
+            <thead>
+                <tr>
+                    <th>#</th>
+                    <th>Label</th>
+                    <th>Runtime</th>
+                    <th>Status</th>
+                    <th>Path</th>
+                </tr>
+            </thead>
+            <tbody id="schedule-table-body"></tbody>
+        </table>
+    </div>
+    <p id="schedule-status" class="status-line" aria-live="polite">Loading schedule...</p>
+</div>