Improve the editing interaction or style of nodes such as list operators in dark mode

### Self Checks

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- [x] I have searched for existing issues [search for existing issues](https://github.com/langgenius/dify/issues), including closed ones.
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### 1. Is this request related to a challenge you're experiencing? Tell me about your story.

I am trying to quick-start and encountered an issue where the list operator couldn't rename.

It wasn't until I found a video of renaming in an [issue](https://github.com/langgenius/dify/issues/13281) that I realized it was ok and the function was ok.

At first, I thought I couldn't rename it because I didn't see the edit button or any prompts, and the interaction wasn't clear enough. For the first time using it, there were indeed some difficulties

If it can be improved, it should be even better.

### 2. Additional context or comments

In dark mode and Version1.15.0.

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edit screenshot

### 3. Can you help us with this feature?

- [ ] I am interested in contributing to this feature.

Start by reproducing the list operator editing flow in dark mode, using the node shown in the report as the entry point. Inspect how renaming is presented and make the edit affordance or interaction clear to a first-time user; done means the rename action is discoverable without external guidance.

Written by the indexing model from the issue text.