Enable biome linting strict

[andeplane]

Enable Biome linting and enforce unused variables as errors.

This PR replaces the existing linting setup with Biome, adds lint and lint:fix scripts, and configures Biome to treat unused variables as errors.

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[cursor]

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[gemini-code-assist]

Summary of Changes

Hello @andeplane, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request transitions the project's linting infrastructure to Biome, a modern code formatter and linter. The primary goal is to enhance code quality and maintainability by enforcing stricter rules, particularly by treating unused variables as errors, and providing streamlined commands for linting and automatic code fixes.

Highlights

• Biome Integration: The existing linting setup has been replaced with Biome, a modern code formatter and linter.
• Strict Linting Rules: Biome is configured to enforce stricter code quality by treating unused variables as errors.
• New NPM Scripts: Convenience scripts lint and lint:fix have been added to package.json for easy execution of Biome checks and automatic fixes.

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[gemini-code-assist]

Code Review

This pull request introduces Biome for linting and formatting, which is a great step towards improving code quality and consistency. The configuration in biome.json is a good start. I've made a couple of suggestions to refine it: one to make the file inclusion patterns more specific for better performance, and another to align the linting rules with the 'strict' goal mentioned in the pull request title. The changes to package.json and package-lock.json look correct.

[gemini-code-assist]

While vcs.useIgnoreFile is helpful, specifying includes more explicitly is a best practice. Using "**" can be slow as it traverses all directories, which might include build artifacts or other files that are not in .gitignore but are not meant to be linted. Scoping it down to your source files will improve performance and prevent unintended linting.

Suggested change

	"files": {
	"ignoreUnknown": false,
	"includes": ["**"]
	},
	"files": {
	"ignoreUnknown": false,
	"includes": ["src/**/*.{ts,tsx,js,jsx}"]
	},

[gemini-code-assist]

The PR title mentions enabling 'strict' linting, but the configuration only uses the recommended rules. Biome offers a strict preset which enables more opinionated rules for higher code quality. If the intention is to be strict, you could replace "recommended": true with "strict": true.

This would enable all strict rules and keep your override for unused variables. If you only intended to enable the recommended rules, consider updating the PR title to avoid confusion.

Suggested change

	"recommended": true,
	"correctness": {
	"noUnusedVariables": "error"
	}
	"strict": true,
	"correctness": {
	"noUnusedVariables": "error"
	}