chore: overhaul devdeps

[nissy-dev]

No description provided.

[Copilot]

Pull Request Overview

This PR modernizes the project's development dependencies and configuration files, upgrading to the latest versions of build tools and linters while migrating to newer configuration formats.

• Upgrades major dev dependencies (ESLint 9, TypeScript 5.9, Vitest 4, Prettier 3)
• Migrates configuration files to modern formats (ESLint flat config, vitest.config.mts)
• Removes husky/commitlint tooling in favor of release-please workflow
• Replaces TypeScript path aliases with relative imports for better compatibility

Reviewed Changes

Copilot reviewed 32 out of 36 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
package.json	Updates dev dependencies to latest versions, removes husky/commitlint, adjusts Node.js engine requirement
vitest.config.ts → vitest.config.mts	Migrates to .mts extension and updates import from "vite" to "vitest/config"
tsconfig.json	Switches from @tsconfig/node18 to @tsconfig/node-lts, removes path aliases and esModuleInterop
eslint.config.js	New ESLint flat config replacing .eslintrc.js with updated rule configurations
.eslintrc.js, .eslintignore, .commitlintrc.js	Removed legacy configuration files
.husky/commit-msg	Removed husky git hook
src/**/*.ts	Adds trailing commas to function parameters for Prettier consistency
tests/**/*.test.ts	Replaces "@/" import aliases with relative paths, updates fs mock to inline factory pattern
tests/helpers/fsMock.ts	New helper implementing fs mock as factory function for Vitest
mocks/fs.ts	Removed manual mock directory in favor of inline factory pattern
README.md, FOR_DEVELOPMENT.md	Updates documentation to remove outdated version requirements
.npmignore	Updates ignored files to reflect new configuration file names

Files not reviewed (2)

• tests/integration/analyze/managed-by-pnpm/pnpm-lock.yaml: Language not supported
• tests/integration/extract/managed-by-pnpm/pnpm-lock.yaml: Language not supported

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