chore: upgrade dev dependencies to latest major versions

[guyinwonder168]

Summary

• Upgrade @biomejs/biome 1.9.4 → 2.4.10 (auto-migrated config via biome migrate)
• Upgrade typescript 5.9.3 → 6.0.2
• Upgrade vitest 3.2.4 → 4.1.2
• Upgrade @vitest/coverage-v8 3.2.4 → 4.1.2
• Upgrade @types/node 22.19.15 → 25.5.2
• Bump minimum Node.js version from 18 to 20

Breaking Changes

Biome 1→2

• organizeImports.enabled migrated to assist.actions.source.organizeImports
• Config auto-migrated via npx @biomejs/biome migrate --write

TypeScript 5→6

• types now defaults to [] — our tsconfig already has "types": ["node"] ✅
• rootDir now defaults to . — our tsconfig already has "rootDir": "./src" ✅

Vitest 3→4

• Pool architecture rewritten (tinypool removed)
• V8 coverage provider uses new AST-based remapping
• No config changes needed for our setup

Node.js

• Vitest 4 requires Node.js >= 20

Verification

• ✅ 124/124 tests pass
• ✅ Typecheck clean (TypeScript 6.0.2)
• ✅ Lint clean (Biome 2.4.10)
• ✅ Coverage 99.14% lines
• ✅ Build clean

Wiki Updated

• Home.md — Changelog section updated
• Development.md — Node.js >= 20, TypeScript >= 6.0

[kilo-code-bot]

Code Review Summary

Status: No Issues Found | Recommendation: Merge

Overview

This PR upgrades development dependencies to their latest major versions:

• @biomejs/biome: 1.9.4 → 2.4.10
• typescript: 5.9.3 → 6.0.2
• vitest: 3.2.4 → 4.1.2
• @vitest/coverage-v8: 3.2.4 → 4.1.2
• @types/node: 22.19.15 → 25.5.2
• Node.js minimum: 18 → 20

Changes Reviewed

File	Changes
package.json	Version bumps, engines update
biome.json	Schema update, config migration
CHANGELOG.md	Dependency update entries
README.md	Prerequisites updated
package-lock.json	Regenerated

All changes are configuration-only; no source code was modified. The breaking changes are properly documented in the PR description and the migration appears complete (Biome config auto-migrated).

Verification

PR states: ✅ 124/124 tests pass, ✅ Typecheck clean, ✅ Lint clean, ✅ Coverage 99.14%, ✅ Build clean.

Files Reviewed (5 files)

• package.json
• biome.json
• CHANGELOG.md
• README.md
• package-lock.json

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_{Reviewed by minimax-m2.5-20260211 · 535,030 tokens}