feat: Next.js 16 , zod v4 ,minor version bumps and minor fixes

[HimanshuKumarDutt094]

Closes #2157 #2082 #2163 #1903

✅ Checklist

• I have followed every step in the contributing guide (updated 2022-10-06).
• The PR title follows the convention we established conventional-commit
• I performed a functional test on my final commit

---

Changelog

• upgraded nextjs to v16 , update zod to v4 and all vercel env preset , updated eslint setup as next lint is no longer supported.

• removed postcss as nextjs auto supports it see nextjs docs

• moved from env.js and next.config.js to ts variant as its supported now (closes feat: Use TypeScript Next.js config (next.config.ts) #2082 )

• added nextCookies plugin following better auth new docs (closes bug: Error Code: state_mismatch when signing in with GitHub on fresh T3 App #2157 )

• upgraded astro version and headless ui menu,listbox component imports (minor change)

• add generated folder to base template gitignore (closes bug: /generated being pushed #2163)

• add [alias] to import-alias option (closes: bug: Setting import-alias via the command line fails. #1903)

• note: no cache component feature used as of now

💯

[changeset-bot]

🦋 Changeset detected

Latest commit: bf2c821

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
create-t3-app	Patch

Not sure what this means? Click here to learn what changesets are.

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

[socket-security]

Review the following changes in direct dependencies. Learn more about Socket for GitHub.

Diff	Package	Supply Chain Security	Vulnerability	Quality	Maintenance	License
	@​astrojs/​tailwind@​6.0.1 ⏵ 6.0.2
	@​astrojs/​check@​0.9.4 ⏵ 0.9.5	-9		+1	-1
	@​astrojs/​sitemap@​3.3.0 ⏵ 3.6.0	+1		+2	-3
	@​astrojs/​vercel@​8.1.3 ⏵ 9.0.0	+1		+2
	@​t3-oss/​env-nextjs@​0.12.0 ⏵ 0.13.8			+26
	astro@​5.5.4 ⏵ 5.15.7		+25	+1
	eslint-plugin-import-x@​4.9.1 ⏵ 4.16.1	+1		+1	-1
	prettier-plugin-tailwindcss@​0.6.11 ⏵ 0.6.14				+2
	@​tailwindcss/​postcss@​4.0.15 ⏵ 4.1.16	+1		+22	+1
	@​astrojs/​react@​4.2.1 ⏵ 4.4.2	+1		+20	+6
	@​astrojs/​mdx@​4.2.1 ⏵ 4.3.10	+2		+20	+5

View full report

[HimanshuKumarDutt094]

This is wip I want to add activity and view transition+ cache component, will continue in a few days

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Preview	Comments	Updated (UTC)
create-t3-app	Ready	Preview	Comment	Nov 18, 2025 3:04am

[socket-security]

Warning

Review the following alerts detected in dependencies.

According to your organization's Security Policy, it is recommended to resolve "Warn" alerts. Learn more about Socket for GitHub.

Action	Severity	Alert  (click "▶" to expand/collapse)
Warn		Obfuscated code: npm safer-buffer is 94.0% likely obfuscated Confidence: 0.94 Location: Package overview From: pnpm-lock.yaml → npm/@changesets/cli@2.27.3 → npm/safer-buffer@2.1.2 ℹ Read more on: This package | This alert | What is obfuscated code? Next steps: Take a moment to review the security alert above. Review the linked package source code to understand the potential risk. Ensure the package is not malicious before proceeding. If you're unsure how to proceed, reach out to your security team or ask the Socket team for help at support@socket.dev. Suggestion: Packages should not obfuscate their code. Consider not using packages with obfuscated code. Mark the package as acceptable risk. To ignore this alert only in this pull request, reply with the comment @SocketSecurity ignore npm/safer-buffer@2.1.2. You can also ignore all packages with @SocketSecurity ignore-all. To ignore an alert for all future pull requests, use Socket's Dashboard to change the triage state of this alert.

View full report