feat: add gallery page with image and video details, including upload and generation status

Co-authored-by: Copilot <copilot@github.com>

frontend/app/templates/image_detail.html

@@ -0,0 +1,35 @@
+{% extends "base.html" %} {% block title %}Generated Image{% endblock %} {%
+block content %}
+<div class="container mx-auto px-4 py-8">
+  <a
+    href="{{ url_for('gallery') }}"
+    class="text-blue-400 hover:underline mb-4 inline-block"
+    >&larr; Back to Gallery</a
+  >
+
+  {% if image %}
+  <h1 class="text-2xl font-bold mb-4">Generated Image</h1>
+  <div class="bg-gray-800 rounded-lg shadow-lg overflow-hidden">
+    <img
+      src="{{ image.image_data }}"
+      alt="{{ image.prompt }}"
+      class="w-full object-contain"
+    />
+    <div class="p-6">
+      <h2 class="text-xl font-semibold mb-2">Prompt</h2>
+      <p class="text-gray-300 bg-gray-900 p-3 rounded-md">{{ image.prompt }}</p>
+      <div class="mt-4 text-sm text-gray-400">
+        <p><strong>Model:</strong> {{ image.model_id }}</p>
+        <p>
+          <strong>Created:</strong> {{ image.created_at | fromisoformat |
+          humantime }}
+        </p>
+      </div>
+    </div>
+  </div>
+  {% else %}
+  <h1 class="text-2xl font-bold">Image not found</h1>
+  <p class="text-gray-400 mt-2">Could not find details for this image.</p>
+  {% endif %}
+</div>
+{% endblock %}