feat(frontend): restyle format picker and add file size to the config card

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

frontend/src/components/FileConfigCard.jsx

@@ -1,4 +1,5 @@
 import { File as FileIcon } from '@phosphor-icons/react';
+import { formatBytes } from '../utils/formatBytes.js';
 
 const QUALITY_FORMATS = ['jpg', 'jpeg', 'webp', 'avif', 'tiff'];
 const ICON_SIZES = [16, 32, 48, 256, 512];
@@ -7,21 +8,28 @@ const DEFAULT_ICON_SIZE = 256;
 export function FileConfigCard({ item, index, t, onTargetFormatChange, onQualityChange, onIconSizeChange }) {
   return (
     <li className="file-config-card">
-      <FileIcon size={24} weight="regular" />
-      <span className="file-config-name">{item.file.name}</span>
+      <div className="file-tile-header">
+        <FileIcon size={24} weight="regular" />
+        <span className="file-tile-name">{item.file.name}</span>
+        <span className="file-tile-size">{formatBytes(item.file.size)}</span>
+      </div>
 
       {item.targets.length > 0 ? (
         <div className="file-config-controls">
-          <select
-            value={item.targetFormat ?? ''}
-            onChange={(event) => onTargetFormatChange(index, event.target.value)}
-          >
-            {item.targets.map((target) => (
-              <option key={target} value={target}>
-                {target}
-              </option>
-            ))}
-          </select>
+          <div className="format-select-group">
+            <select
+              className="format-select"
+              value={item.targetFormat ?? ''}
+              onChange={(event) => onTargetFormatChange(index, event.target.value)}
+            >
+              {item.targets.map((target) => (
+                <option key={target} value={target}>
+                  {target}
+                </option>
+              ))}
+            </select>
+            {item.targetFormat && <span className="format-badge">{item.targetFormat.toUpperCase()}</span>}
+          </div>
 
           {QUALITY_FORMATS.includes(item.targetFormat) && (
             <label>