README: point thumbnail to new Space-hosted brand card

README.md

@@ -26,12 +26,12 @@ models:
   - deepseek-ai/DeepSeek-V3
   - deepseek-ai/DeepSeek-R1
   - Qwen/Qwen2.5-32B
-thumbnail: https://quicksilverpro.io/og.png
+thumbnail: https://huggingface.co/spaces/MachineFi/QuickSilverPro-Chat/resolve/main/thumbnail.png
 ---
 
-<!-- Thumbnail uses the existing site OG image (1200×630 indigo-purple brand
-card). HF will automatically generate one from colorFrom/colorTo if this URL
-is unreachable — safe fallback. -->
+<!-- Thumbnail is 1200×630, indigo-purple brand card with 3 model pills
+(DeepSeek V3, R1, Qwen 3.5) — optimized for HF listing click-through.
+Source SVG lives locally; regenerate with headless Chrome if editing. -->
 
 
 # QuickSilver Pro Chat