test(frontend): add vitest test suite and apply code formatting

frontend/public/admin/dashboard.html

@@ -1,21 +1,21 @@
 <h1>Dashboard</h1>
 <div class="stat-grid">
-    <article class="stat-card">
-        <h2>Concurrent Viewers</h2>
-        <p id="stat-viewers" class="stat-value">0</p>
-    </article>
-    <article class="stat-card">
-        <h2>Stored Messages</h2>
-        <p id="stat-stored-messages" class="stat-value">0</p>
-    </article>
-    <article class="stat-card">
-        <h2>Moderation Actions</h2>
-        <p id="stat-moderation-actions" class="stat-value">0</p>
-    </article>
-    <article class="stat-card">
-        <h2>Media Runtime</h2>
-        <p id="stat-media-runtime" class="stat-value">00:00:00</p>
-        <p id="stat-media-count" class="stat-caption">0 files</p>
-    </article>
+  <article class="stat-card">
+    <h2>Concurrent Viewers</h2>
+    <p id="stat-viewers" class="stat-value">0</p>
+  </article>
+  <article class="stat-card">
+    <h2>Stored Messages</h2>
+    <p id="stat-stored-messages" class="stat-value">0</p>
+  </article>
+  <article class="stat-card">
+    <h2>Moderation Actions</h2>
+    <p id="stat-moderation-actions" class="stat-value">0</p>
+  </article>
+  <article class="stat-card">
+    <h2>Media Runtime</h2>
+    <p id="stat-media-runtime" class="stat-value">00:00:00</p>
+    <p id="stat-media-count" class="stat-caption">0 files</p>
+  </article>
 </div>
-<p id="overview-status" class="status-line" aria-live="polite">Loading live admin overview...</p>
+<p id="overview-status" class="status-line" aria-live="polite">Loading live admin overview...</p>