feat: enhance model caching and output modalities handling

- Updated `refresh_models_cache` to include output modalities in the models cache.
- Added `get_model_output_modalities` function to retrieve output modalities for a specific model.
- Modified tests to cover new functionality for output modalities.
- Updated OpenRouter video generation functions to support audio generation and improved error handling.
- Enhanced dashboard to display generated images and videos.
- Refactored frontend templates to accommodate new data structures for generated content.
- Adjusted tests to validate changes in model handling and dashboard rendering.

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

frontend/app/templates/dashboard.html

@@ -6,7 +6,59 @@ endblock %} {% block content %}
   <a href="{{ url_for('generate') }}" class="btn">Start generating</a>
 </div>
 
-{% if images %}
+{% if generated_images %}
+<div class="card mt-2">
+  <h2>Generated images</h2>
+  <div class="image-grid">
+    {% for img in generated_images %}
+    <div class="image-grid-item">
+      <img
+        src="{{ img.image_data }}"
+        alt="{{ img.prompt }}"
+        class="generated-image"
+        loading="lazy"
+      />
+      <p class="text-muted" style="font-size: 0.75rem; margin-top: 0.25rem">
+        <strong>{{ img.model_id }}</strong><br />{{ img.prompt[:80] }}{% if
+        img.prompt|length > 80 %}…{% endif %}
+      </p>
+    </div>
+    {% endfor %}
+  </div>
+</div>
+{% endif %} {% if generated_videos %}
+<div class="card mt-2">
+  <h2>Generated videos</h2>
+  <div class="image-grid">
+    {% for vid in generated_videos %}
+    <div class="image-grid-item">
+      {% if vid.video_url %}
+      <video controls style="max-width: 100%; border-radius: 6px">
+        <source src="{{ vid.video_url }}" />
+        Your browser does not support the video tag.
+      </video>
+      {% else %}
+      <div
+        style="
+          background: #1a1a1a;
+          border-radius: 6px;
+          padding: 2rem;
+          text-align: center;
+        "
+      >
+        <span class="text-muted">{{ vid.status | capitalize }} &hellip;</span>
+      </div>
+      {% endif %}
+      <p class="text-muted" style="font-size: 0.75rem; margin-top: 0.25rem">
+        <strong>{{ vid.model_id }}</strong><br />{{ vid.prompt[:80] }}{% if
+        vid.prompt|length > 80 %}…{% endif %}<br />
+        <em>{{ vid.status }}</em>
+      </p>
+    </div>
+    {% endfor %}
+  </div>
+</div>
+{% endif %} {% if images %}
 <div class="card mt-2">
   <h2>Uploaded reference images</h2>
   <div class="image-grid">