Fix emoji sizing in picker to match unicode and custom emoji

- Reduce unicode emoji from text-2xl (24px) to text-xl (20px)
- Reduce custom emoji from w-6 h-6 (24px) to size-5 (20px)
- Both now render at same 20px size for visual consistency
- Fixes custom emoji appearing too large compared to unicode emoji

src/components/chat/EmojiPickerDialog.tsx

@@ -176,12 +176,12 @@ export function EmojiPickerDialog({
                 title={`:${result.shortcode}:`}
               >
                 {result.source === "unicode" ? (
-                  <span className="text-2xl leading-none">{result.url}</span>
+                  <span className="text-xl leading-none">{result.url}</span>
                 ) : (
                   <img
                     src={result.url}
                     alt={`:${result.shortcode}:`}
-                    className="w-6 h-6 object-contain"
+                    className="size-5 object-contain"
                   />
                 )}
               </button>