'Continue Learning' Button Bug

### Describe the Issue

When you have finished the end of a chapter in a course, the '**Continue Learning**' button should redirect you to the next lesson of the next chapter. But it instead redirects me to the last completed lesson of the last chapter. This may be an issue for all courses, but I have not verified that.

### Affected Page

https://www.freecodecamp.org/learn/javascript-v9/#quiz-javascript-loops

### Steps to Reproduce

1. Go to JavaScript course
2. Finish the last lesson of a chapter in that course
3. Click on 'Continue Learning'
4. Get redirected to the last completed lesson instead of the next uncompleted one

### Expected behavior

I expect the '**Continue Learning**' button to take me to whatever the next uncompleted lesson is.

As shown in the attached screen recording below, I have already finished the `JavaScript Loops Quiz` lesson. When I click on the 'Continue Learning' button, I expect to be taken to `What Is a String Object, and How Does It Differ from String Primitive?`. But instead I'm taken back to the completed `JavaScript Loops Quiz` lesson.

### Screenshots

https://github.com/user-attachments/assets/f2cd6625-9737-4896-8811-fb19478796ef

### System

- Device: Windows Laptop
- OS: Windows 11 Pro (Version: 25H2, Build: 26200.9168)
- Browser: Brave, Google Chrome
- Version: Brave: v1.94.119, Chrome: 152.0.7977.65

### Additional context

[Discord exchange on JS Arrays quiz](https://discord.com/channels/692816967895220344/1524492096097095901/1527317084189495396)

Start on the affected JavaScript course page and reproduce the bug by completing the final lesson of a chapter, then clicking Continue Learning. Trace the navigation decision for the button and verify that it opens the next uncompleted lesson, such as What Is a String Object, rather than the completed lesson.

Written by the indexing model from the issue text.