feat: add video reuse — re-analyze previous uploads without re-uploading

templates/index.html

@@ -45,6 +45,57 @@
     cursor: pointer;
   }
 
+  /* Existing videos section */
+  .existing-videos-section { margin-top: var(--space-8); }
+  .section-title {
+    font-size: var(--text-lg);
+    font-weight: var(--font-semibold);
+    margin-bottom: var(--space-4);
+  }
+  .video-list {
+    display: grid;
+    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
+    gap: var(--space-4);
+  }
+  .video-item {
+    background: var(--color-neutral-50);
+    border: 2px solid var(--color-neutral-200);
+    border-radius: var(--radius-lg);
+    padding: var(--space-4);
+    cursor: pointer;
+    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
+    display: flex;
+    align-items: center;
+    gap: var(--space-3);
+  }
+  .video-item:hover {
+    border-color: var(--color-neutral-300);
+    box-shadow: var(--shadow-sm);
+  }
+  .video-item.selected {
+    border-color: var(--color-primary);
+    box-shadow: 0 0 0 3px color-mix(in srgb, var(--color-primary) 12%, transparent);
+  }
+  .video-item-radio {
+    flex-shrink: 0;
+    width: 18px;
+    height: 18px;
+    accent-color: var(--color-primary);
+    cursor: pointer;
+  }
+  .video-item-info { flex: 1; min-width: 0; }
+  .video-item-name {
+    font-weight: var(--font-medium);
+    color: var(--color-neutral-800);
+    font-size: var(--text-sm);
+    word-break: break-word;
+  }
+  .video-item-meta {
+    font-size: var(--text-xs);
+    color: var(--color-neutral-500);
+    margin-top: var(--space-1);
+  }
+
   /* File info */
   .file-info {
     margin-top: var(--space-4);
@@ -215,6 +266,8 @@
 </div>
 
 <form action="/upload" method="post" enctype="multipart/form-data" id="upload-form">
+  <input type="hidden" name="video_path" id="video-path-input" value="">
+
   {# --- Upload Zone --- #}
   <div class="upload-zone" id="upload-zone" role="button" tabindex="0" aria-label="Upload video file">
     <span class="upload-zone-icon" aria-hidden="true">&#128190;</span>
@@ -237,6 +290,12 @@
     </div>
   </div>
 
+  {# --- Existing Videos --- #}
+  <div class="existing-videos-section" id="existing-videos-section" style="display:none">
+    <h3 class="section-title">Or use a previously uploaded video</h3>
+    <div class="video-list" id="video-list"></div>
+  </div>
+
   {# --- Model Selection --- #}
   <div class="model-section">
     <div class="model-section-header">