UI header logos: add fallback to show first 3 images from assets when keywords not matched

app.py

@@ -100,8 +100,11 @@ def _find_ui_header_logos(root: Path):
     order = []
     for key in ("camel", "tvg", "waterloo"):
         p = pick(key)
-        if p:
+        if p and p not in order:
             order.append(p)
+    # Fallback: if none matched, take up to 3 images in stable order
+    if not order and imgs:
+        order = imgs[:3]
     return order
 
 def _ui_header_logos_html():