chore(nextjs)!: Throw when missing encryption key

[brkalow]

Description

When passing a secret key at runtime to clerkMiddleware(), we need a stable encryption key to safely pass the value from the middleware to the application server. Previously, we avoided throwing an error to prevent a breaking change. Now that we're releasing a major, we are changing this to throw an error.

fixes USER-3057

Checklist

• pnpm test runs as expected.
• pnpm build runs as expected.
• (If applicable) JSDoc comments have been added or updated for any package exports
• (If applicable) Documentation has been updated

Type of change

• 🐛 Bug fix
• 🌟 New feature
• 🔨 Breaking change
• 📖 Refactoring / dependency upgrade / documentation
• other:

[changeset-bot]

🦋 Changeset detected

Latest commit: 32e5469

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

This PR includes changesets to release 1 package

Name	Type
@clerk/nextjs	Major

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Project	Deployment	Preview	Comments	Updated (UTC)
clerk-js-sandbox	Ready	Preview	Comment	Dec 3, 2025 8:57pm

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✨ Finishing touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch brk.chore/throw-on-missing-encryption-key

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[brkalow]

!allow-major

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commit: 32e5469

[LauraBeatris]

Thanks for that! 🫡