fix(apollo-react): separate warning styles from paused styles in stage components

Remove yellow border for Warning status on StageContainer, StageTask, and
execution status borders. Warning now only shows the icon, while Paused
retains the yellow border and pulse animation.

https://claude.ai/code/session_01L8FQaVQLtdZSxJWAe4eBP3

Author: claude

packages/apollo-react/src/canvas/components/StageNode/StageNode.styles.ts

@@ -48,7 +48,7 @@ export const StageContainer = styled.div<{
     `}
 
   ${({ status }) =>
-    (status === 'Paused' || status === 'Warning') &&
+    status === 'Paused' &&
     css`
       border-color: var(--uix-canvas-warning-icon);
     `}
@@ -210,7 +210,7 @@ export const StageTask = styled.div<{
     `}
 
   ${({ status }) =>
-    (status === 'Paused' || status === 'Warning') &&
+    status === 'Paused' &&
     css`
       border-color: var(--uix-canvas-warning-icon);
     `}