fix(component): loading in button should be white for primary variant (#10073)

close AF-2178

packages/frontend/component/src/ui/loading/loading.tsx

@@ -8,12 +8,14 @@ export interface LoadingProps {
   size?: number | string;
   speed?: number;
   progress?: number;
+  strokeColor?: string;
 }
 
 export const Loading = ({
   size,
   speed = 1.2,
   progress = 0.2,
+  strokeColor,
 }: LoadingProps) => {
   // allow `string` such as `16px` | `100%` | `1em`
   const sizeWithUnit = size ? withUnit(size, 'px') : '16px';
@@ -43,10 +45,11 @@ export const Loading = ({
         cy={12}
         r={8}
         strokeWidth={4}
-        stroke="var(--affine-primary-color)"
+        stroke={strokeColor || 'var(--affine-primary-color)'}
         strokeDasharray={`${2 * Math.PI * 8 * progress} ${
           2 * Math.PI * 8 * (1 - progress)
         }`}
+        strokeLinecap="round"
       />
     </svg>
   );