fix(site): update Next.js basePath to spectrum-design-data

[GarthDB]

Summary

This is the ACTUAL fix that was meant to be in PR #633 but was accidentally omitted.

The critical next.config.js change was left uncommitted when #633 was created, so the site is still loading assets from /spectrum-tokens/ paths, causing fonts and other assets to fail.

Changes

• Updated basePath from /spectrum-tokens to /spectrum-design-data
• Updated assetPrefix from /spectrum-tokens/ to /spectrum-design-data/

What Happened

PR #633 successfully merged:

• ✅ All package.json repository URL updates
• ✅ Changeset file
• ❌ The next.config.js changes (accidentally left uncommitted)

This PR contains only the missing config file change.

After Merge

The site will rebuild and fonts/assets will load correctly at:

• https://opensource.adobe.com/spectrum-design-data/

Related: #633

[changeset-bot]

⚠️ No Changeset found

Latest commit: 7bf4c37

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR

[GarthDB]

Run report for 7bf4c37e

Total time: 25.1s | Comparison time: 23.8s | Estimated loss: 1.3s (5.2% slower)

	Action	Time	Status	Info
⬛️	SetupProto(0.51.4)	0.1ms	Skipped
🟩	SyncWorkspace	7ms	Passed
🟩	SyncProject(componentSchemas)	648.2ms	Passed
🟩	SyncProject(site)	0.3ms	Passed
🟩	RunTask(site:copyComponentSchema)	543.3ms	Passed
🟩	RunTask(site:copyTokenTypeSchema)	555.6ms	Passed
⬛️	SetupToolchain(node:~20.12)	1.3s	Skipped
🟩	InstallWorkspaceDeps(node:~20.12)	8.2s	Passed
🟩	RunTask(site:clean)	138.2ms	Passed
🟩	RunTask(site:build)	15.6s	Passed
🟩	RunTask(site:export)	106.6ms	Passed

Touched files

docs/site/next.config.js