[MPDX-8445] Next.js v15 upgrade

[canac]

Description

Upgrade to Next.js v15. There are lots of breaking changes in the v15 release but not in features that we are using: https://nextjs.org/docs/app/building-your-application/upgrading/version-15.

I only needed to remove the swcMinify config option that started defaulting to true in Next.js 13 and was removed in Next.js 15.

I also migrated next.config.js to next.config.ts now that Next.js supports TypeScript config files.

MPDX-8445

Checklist:

• I have given my PR a title with the format "MPDX-(JIRA#) (summary sentence max 80 chars)"
• I have applied the appropriate labels. (Add the label "On Staging" to get the branch automatically merged into staging.)
• I have requested a review from another person on the project

[github-actions]

Bundle sizes [mpdx-react]

Compared against 51a722f

Route	Size (gzipped)	Diff
/404	82.5 KB	+1007 B
/500	82.46 KB	+1006 B
/_app	371.56 KB	-4.42 KB
/accountLists	120.18 KB	+1003 B
/accountLists/[accountListId]/contacts/flows/setup	166 KB	+1.08 KB
/accountLists/[accountListId]/settings/admin	132.32 KB	+1.14 KB
/accountLists/[accountListId]/settings/integrations	155.52 KB	+1.06 KB
/accountLists/[accountListId]/settings/manageAccounts	138.19 KB	+1.11 KB
/accountLists/[accountListId]/settings/manageCoaches	134.86 KB	+1.14 KB
/accountLists/[accountListId]/settings/notifications	134.27 KB	+1.09 KB
/accountLists/[accountListId]/settings/organizations	133.79 KB	+1.14 KB
/accountLists/[accountListId]/tools/appeals	183.11 KB	+1.05 KB
/accountLists/[accountListId]/tools/fix/emailAddresses/[[...contactId]]	159.24 KB	+1.08 KB
/accountLists/[accountListId]/tools/fix/phoneNumbers/[[...contactId]]	140.88 KB	+1.07 KB
/accountLists/[accountListId]/tools/import/google	154.34 KB	+1.08 KB
/accountLists/[accountListId]/tools/import/tnt	149.33 KB	+1.07 KB
/login	120.42 KB	+1023 B
/logout	82.29 KB	+1013 B
/setup/connect	125.84 KB	+1.14 KB

[github-actions]

Preview branch generated at https://8445-nextjs-15-upgrade.d3dytjb8adxkk5.amplifyapp.com

[dr-bizz]

It mentions that fetch requests are not cached by default. I know we don't use fetch much and might not need to add caching but thought it was worth noting.

The code and the web ap look great.

Also it looks like swcMinify is allowed in Next.js 15 - https://nextjs.org/docs/messages/swc-minify-enabled

[canac]

It mentions that fetch requests are not cached by default. I know we don't use fetch much and might not need to add caching but thought it was worth noting.

@dr-bizz The only places I saw that we were making fetch requests on the server were by Apollo for GraphQL requests. Since GraphQL uses the POST method and Next.js only cached GET requests, we shouldn't be affected by this change.

Also it looks like swcMinify is allowed in Next.js 15 - https://nextjs.org/docs/messages/swc-minify-enabled

That link is just additional info for an error message generated by older Next.js versions. Here's the PR that removed swcMinify: vercel/next.js#65690.