feat(web): refresh palette, simplify ranking toolbar and drop export

tests/test_web_server.py

@@ -119,9 +119,7 @@ def test_readonly_routes_and_static():
             assert status == 404
 
             status, _, payload = running.request("/api/export.csv?sort=view")
-            assert status == 200
-            assert payload.startswith(b"\xef\xbb\xbf")
-            assert "咻咻满".encode("utf-8") in payload
+            assert status == 404
 
             status, headers, _ = running.request("/api/overview")
             assert headers["X-Content-Type-Options"] == "nosniff"