Migrates from next lint to eslint

[simonbs]

Running npm run lint would give the following warning, so these changes migrate the codebase to eslint.

❯ npm run lint

> [email protected] lint
> next lint --max-warnings=0

`next lint` is deprecated and will be removed in Next.js 16.
For new projects, use create-next-app to choose your preferred linter.
For existing projects, migrate to the ESLint CLI:
npx @next/codemod@canary next-lint-to-eslint-cli .

[Copilot]

Pull Request Overview

This PR migrates the linting setup from the deprecated next lint command to the standalone ESLint CLI with a flat configuration format (eslint.config.mjs), as recommended by Next.js 16. The migration includes updating the lint script, creating a new flat config file, and addressing various ESLint violations in the codebase.

Key changes:

• New ESLint flat config file with FlatCompat for backwards compatibility with existing rules
• Fixed React hooks dependency issues by wrapping immediate executions in setTimeout
• Improved TypeScript type definitions, replacing any with more specific types
• Optimized file decoding performance by using Uint8Array directly instead of Blob

Reviewed Changes

Copilot reviewed 12 out of 14 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
eslint.config.mjs	New ESLint v9 flat configuration file migrating from .eslintrc.json
package.json	Updated lint script to use eslint CLI instead of deprecated next lint
types/globals.d.ts	Improved SwaggerUIBundle type from any to function signature
types/@next-auth.d.ts	Removed unused NextAuth import
src/features/sidebar/view/SecondarySplitHeader.tsx	Fixed useEffect hook by wrapping window check in setTimeout and removing isMac from dependencies
src/features/projects/view/ProjectsContextProvider.tsx	Wrapped initial refresh call in setTimeout to satisfy ESLint rules
src/features/encrypt/view/EncryptionForm.tsx	Moved styled component outside render function to prevent recreation
src/features/auth/view/SignInTexts.tsx	Moved helper function and constant to module scope to prevent recreation on each render
src/common/utils/fileUtils.ts	Optimized file decoding by using Uint8Array directly instead of Blob/arrayBuffer
test/projects/GitHubRepositoryDataSource.test.ts	Changed let to const for variable that's never reassigned
test/common/utils/saneParseInt.test.ts	Changed @ts-ignore to @ts-expect-error for better type safety
test/common/github/OAuthTokenRefreshingGitHubClient.test.ts	Changed let to const for variable that's never reassigned
test/auth/OAuthTokenRepository.test.ts	Replaced any[] types with specific tuple types for better type safety
test/auth/AuthjsAccountsOAuthTokenRepository.test.ts	Replaced any[] with readonly unknown[] for better type safety

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