chore: replace eslint and prettier with biome

[designcode]

What

Replace ESLint + Prettier with Biome as a single lint/format toolchain, matching the storage repo's setup.

Changes

• Add @biomejs/biome@2.5.2 + biome.json — mirrors the storage repo: Prettier-equivalent formatting (single quotes, semicolons, es5 trailing commas, width 80) and ESLint rules mapped to Biome's recommended set plus noExplicitAny/noUnusedVariables.
• Remove eslint, @eslint/js, typescript-eslint, eslint-plugin-simple-import-sort, prettier, and eslint.config.js / .prettierrc.
• Repoint lint/lint:fix/format/format:check scripts at Biome (+ new check/check:fix); switch the husky pre-commit to npm run check. Script names are unchanged, so CI/release.yaml need no edits.
• Apply Biome's formatter, import organizer, and recommended-rule autofixes across src/test/scripts (49 files) — node: imports, literal keys, template strings, Number.isNaN, optional chaining.

Notes

• Restored declare var __TIGRIS_JSON_MODE in global.d.ts — Biome's noVar autofix had changed it to let, which breaks the globalThis augmentation (tsc failed across 10 files). Added a biome-ignore for that line (the original had an equivalent eslint-disable). Plus 3 hand-fixed non-autofixable findings (two forEach block bodies, one stats type).
• Verified: npm run build (tsc + tsup) ✓, biome check clean ✓, npm test 714/714 ✓. No eslint/prettier references remain.
• Independent of the changesets migration branch; the two will conflict in package.json scripts/devDeps and .husky/pre-commit when both merge (trivial to resolve).

🤖 Generated with Claude Code

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Note

Low Risk
Dev-only tooling and mechanical style fixes; runtime CLI behavior is unchanged per the changeset.

Overview
Replaces the ESLint + Prettier dev toolchain with Biome (@biomejs/biome@2.5.2 and new biome.json), aligned with formatting and lint rules similar to the prior setup. Removes eslint.config.js, .prettierrc, and related npm devDependencies.

Scripts now call Biome for lint, format, and new check / check:fix; the husky pre-commit hook runs a single npm run check instead of separate lint and format checks. A changeset documents this as an internal patch with no published CLI behavior change.

The bulk of the diff is Biome-driven autofixes across src, test, and scripts (e.g. node: imports, template literals, Number.isNaN, optional chaining). global.d.ts keeps declare var __TIGRIS_JSON_MODE with a biome-ignore so global augmentation still typechecks after Biome’s noVar autofix.

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