feat: add support for short versions

[LeahMarieBush]

Description

Asana task

This PR adds support for short versions in UDR. There is a partner PR that will be merged around the same time as this one for dev portal here.

The main changes in this PR are as follows:

• Use coerce function from semver to coerce the short versions into semantic versions (ex. v2.x -> 2.0.0). This allows these versions to be properly sorted and compared to other versions for content exclusion.
• Add short version regex to vault content exclusion
• Adds tests for the changes above

Testing

This PR needs to be tested with the changes for dev-portal. Without those changes, the ones in this PR will not work. You will need to locally run UDR and dev-portal to see these changes reflected.

First, do the steps in UDR:
UDR:

1. Checkout leah/feat/short-version
2. Go to vault and create a few new versions. You can do this by copying the latest version folder and pasting it and then changing the name. For testing the sorting, use a variety of version names (ex. v2.x, v3.x, v4.x (rc), v5.x (beta))
3. Run npm run prebuild
4. After that finishes, run npm run dev

Then do the steps in dev-portal:
Dev-portal:

1. Checkout leah/feat/short-version
2. In the .env file, change the UNIFIED_DOCS_API to http://localhost:8080
3. Run npm start
4. Go to http://localhost:3000 and click through the vault docs. Verify the new short versions are sorted properly with the existing versions and look as expected

[github-actions]

Vercel Previews Deployed

Name	Status	Preview	Updated (UTC)
Dev Portal	✅ Ready (Inspect)	Visit Preview	Tue Dec 2 22:01:09 UTC 2025
Unified Docs API	✅ Ready (Inspect)	Visit Preview	Tue Dec 2 21:55:06 UTC 2025