feat(cli): respect NO_COLOR environment variable per no-color.org

[lxcario]

The CLI uses ANSI escape codes for the TTY progress ticker (\x1b[2K\r). The NO_COLOR standard says tools should suppress color/ANSI output when NO_COLOR env is set.

Changes

• Added isNoColor() utility in src/lib/ticker.ts that checks for NO_COLOR in the environment
• When NO_COLOR is set and the terminal is a TTY, the ticker emits plain-text lines via stderrWrite instead of using ANSI escape sequences via rawWrite
• Added a 4th optional noColor parameter to createTicker() (defaults to env detection)
• Added NO_COLOR to the environment variables table in DOCUMENTATION.md
• Added 5 new tests (3 for NO_COLOR ticker behavior + 2 for isNoColor utility)

Testing

• npm run typecheck - clean
• npm run lint:fix - clean
• npx vitest run src/lib/ticker.spec.ts - 19/19 passing (all existing + 5 new)