YNU-620: Add a version switcher and lifecycle scripts

[ihsraham]

the new version switcher and the automation scripts to manage our release lifecycle.

What's new

• Sidebar Switcher: Added a custom version dropdown in the sidebar. It's "page-aware" (keeps you on the same doc when switching) and includes a GitHub link.
• Dynamic Labels: The "Next" version label in the dropdown now auto-updates based on the package.json version.
• Lifecycle Scripts: Added Node.js scripts to automate "freezing" releases and cleaning up, so we don't have to manually delete folders and edit configs.

The Scripts

• npm run version:release <ver> <next>: Freezes current work as <ver> and bumps project to <next>. (Includes validation to prevent skipping versions).
• npm run version:remove <ver>: Safely deletes a specific old version (docs + sidebar + config).
• npm run version:reset <target>: "Factory Reset" — wipes all history and returns to a single-version state.

How to Test (Simple Flow)

1. Release a test version:

   # (Assuming you are currently on 0.5.x)
   npm run version:release 0.5.x 0.6.x

   Result: docs/ is now 0.6.x. You'll see a new versioned_docs/version-0.5.x folder.

2. Verify UI:
   Start the server (npm run start). You should see 0.5.x and 0.6.x in the dropdown.

3. Delete the test version:

   npm run version:remove 0.6.x

   Result: The 0.6.x folder is gone, and you're back to just having 0.5.x docs.

[alessio]

Can this be merged?

[nksazonov]

Incredibly great work, @ihsraham !

[dimast-x]

Great work, the feature works, however some improvements are needed to finalise this story:

According to Figma design, as mentioned in the requirements, the switcher must be in the navbar.

Also, now there is a big empty blank space in the sidebar that seem off.

Lastly, I don't see the version switcher on Mobile.