feat(ui): position current stage badge on node circle

frontend/web/src/components/intelligent_eval/ExecutionProcess.tsx

@@ -143,18 +143,31 @@ function LifecycleTimeline({ ev, currentStage, abnormal }: { ev: IntelligentEval
                   fontSize: 18,
                   transition: 'all 0.3s',
                   border: isCurrent ? `2px solid ${colors.primary}` : 'none',
+                  position: 'relative',
                 }}
               >
                 {isCompleted ? <CheckCircleOutlined /> : <Icon />}
+                {isCurrent && (
+                  <div style={{
+                    position: 'absolute',
+                    top: -8,
+                    right: -8,
+                    background: colors.primary,
+                    color: '#fff',
+                    fontSize: 10,
+                    padding: '2px 6px',
+                    borderRadius: 10,
+                    whiteSpace: 'nowrap',
+                    border: '2px solid #fff',
+                    boxShadow: '0 2px 4px rgba(0,0,0,0.1)',
+                  }}>
+                    当前
+                  </div>
+                )}
               </div>
               <div style={{ fontSize: 12, color: isCurrent ? colors.primary : colors.textSecondary, fontWeight: isCurrent ? 600 : 400, textAlign: 'center' }}>
                 {stage.title}
               </div>
-              {isCurrent && (
-                <Tag color={colors.primary} style={{ fontSize: 11, margin: 0, padding: '0 8px' }}>
-                  当前
-                </Tag>
-              )}
               {time && (
                 <div style={{ fontSize: 11, color: colors.textMuted, textAlign: 'center', marginTop: 2 }}>
                   {formatDateTime(time)}