[Bug] legend in Sankey

### Version

5.2.2

### Link to Minimal Reproduction

https://echarts.apache.org/examples/en/editor.html?code=CYQwLiAEC8kNoChKQN5OZAdiAtgUwC5IByEYgGnWQGNw8BzAewCcBPI4gRmPQF9LkaDFlyESAIwpVItMAxbsS3PgNTTs-DiG6qadJmw4AmHsn7ohGDWNIndM_Qo7Kzqy8msdxO6bPmGSAGZTSHNBdVEOailhPwNFLhDeBABdAG4EPGB6PABnGHgLaVzGAFdmahsyewhmHLAtH2EANxAAG1KxAFZ7OKcSahMVIuES8sqtGIxa-q07aVaOsUDexwDiahdQt2KyiptJGpA6vAaJJoxFzqIADlW5eKih1xGMMf3Jo5Oz4m8p5Cuy3u_gSmySO1Gewm53-kBmp0asMBRE4wMeA2Cw3CkPGBwuyHhP2i9mRkCMaP6Gy2yXSCAQjAADmAAJaMTAFSxtBh4TDAIgoMKQXJ4ZjMvL86RgVgMmy5ECYADWeFYsLaIFYZR-mDZeFhnhIuQVsLwOAZAAsQLlmbl-ZAAGaMailG0kEDAABWIEqmGoKu2dOEoAg9iyOVy9mFXOocmAAFlGMAbDhSm0WQyubDI3ho7a2szMHgAMpSrm26iMNosDjMLLEUL-l7IejMEDm5nUIiIYTuabSmzNsoM2HIUX0M1nABsAAZ7ATGUQZ9IaGbmW1gDXMJ2lxge8ICX3q9mwMO9wAvLnNPBtIgAFlne9yFpltrNeGZY7ORnJkAA7szgGAZpEIE37MEQXQNnuowlmIKD2qu14kAy-ZGpBUEEngAAeYAAMJsnImBnLu6Hnngl6IXe25QbkMG2nI2FRDo9r4YWzKnmInATuQ8FtIhvxqtQqHJOhGCCiJ9G4WydrvraDKMFaLJshw-ZWomdZiehbLUHmglEHapQ-op7IABQMgAlGoInCG0CoFHAtJWRgoZ5AAdA6zAAKJemaxnGZh3HMhZ0AAHyWY5GDMnakB-S5fRsDA0CwFSxAWTZLkMs6PmBRk4WhGZOXhTgrA4RazBgC5wDWgy4DUGaACC0aspgxnEeJB4kGAjD0PQXKFleR4niJQYgAAkryWFEDZ95DeAIAACrtcQzkhI5vD5VRokbcJe4pNI227bwaRAA

### Steps to Reproduce

data = [
{ name: 'a', category: 'Category 1' },
{ name: 'b', category: 'Category 1' },
{ name: 'a1', category: 'Category 2' },
{ name: 'a2', category: 'Category 1' },
{ name: 'b1', category: 'Category 3' },
{ name: 'c', category: 'Category 1' },
];

edges = [
{ source: 'a', target: 'a1', value: 5 },
{ source: 'a', target: 'a2', value: 3 },
{ source: 'b', target: 'b1', value: 8 },
{ source: 'a', target: 'b1', value: 3 },
{ source: 'b1', target: 'a1', value: 1 },
{ source: 'b1', target: 'c', value: 2 },
];

option = {
tooltip: {
trigger: 'item',
triggerOn: 'mousemove',
},
legend: {
show: true,
data: ['Category 1', 'Category 2', 'Category 3'],
selectedMode: 'multiple',
top: 'top',
},
series: [
{
type: 'sankey',
layout: 'none',
data: data,
links: edges,
categories: [
{ name: 'Категория 1', itemStyle: { color: '#5470c6' } },
{ name: 'Категория 2', itemStyle: { color: '#91cc75' } },
{ name: 'Категория 3', itemStyle: { color: '#fac858' } },
],
emphasis: { focus: 'adjacency' },
},
],
};

### Current Behavior

I am using a Sankey diagram. I need to be able to customize the legend so that when clicked, the steps associated with it will disappear

### Expected Behavior

the legend must show

### Environment

```markdown
- OS:
- Browser:
- Framework:
```

### Any additional comments?

_No response_

Start with the linked minimal reproduction and the Sankey configuration, especially the legend data, categories, and selectedMode settings. Trace how Sankey series items are matched to legend entries, then verify that clicking a category hides its associated steps and that the legend displays the intended category names.

Written by the indexing model from the issue text.