[Bug]: Broken Links in "welcome-to-CHAOSS" Slack app.

### Contact Details

onlyoneuche@gmail.com

### What happened?

The Slack app that welcomes new members to the workspace returns broken links (with error 404)

**Step 1:** Display welcome message with CTAs

**Step 2:** User clicks on "Contribute through mentorship"

**Step 3:** Show available mentorship program options

**Step 4:** User selects a mentorship program

**Step 5:** Broken links are returned

### Expected behavior

I expected to see some information about each mentorship program selected

### Your Environment

MacOS

### Steps to Reproduce the Behavior

**Step 1:** Display welcome message with CTAs

**Step 2:** User clicks on "Contribute through mentorship"

**Step 3:** Show available mentorship program options

**Step 4:** User selects a mentorship program

**Step 5:** Broken links are returned

### Relevant log output

_No response_

### Additional Context

_No response_

### Code of Conduct

- [X] I agree to follow this project's Code of Conduct

No file or test is named. Start by reproducing the Slack welcome flow through “Contribute through mentorship,” then inspect the code handling mentorship-program selection and its returned links. Done means each selected program opens without a 404 and displays its expected information.

Written by the indexing model from the issue text.