chore/add linting

[Santiago-j-s]

Stacks over #62

Add development tooling and upgrade Node.js to v22

This PR adds code quality tools and upgrades the project infrastructure:

Development Tools

• Added ESLint with TypeScript support for code linting
• Added Husky pre-push hooks that run:
  • knip for unused code detection
  • TypeScript type checking
  • ESLint linting
• Added new npm scripts for check, knip, and lint

Infrastructure

• Upgraded Node.js from v20 to v22 in Dockerfile and package.json

Code Cleanup

• Removed unused EMOJIS constant and import from constants.ts
• Removed unused isDev export from environment.ts