Add ANSI color support detection for Windows cmd.exe compatibility

[that-github-user]

Summary

src/utils/display.ts uses raw ANSI escape codes for terminal colors. This works on:

• ✅ macOS/Linux terminals
• ✅ Windows Terminal
• ✅ PowerShell 7+
• ❌ Windows cmd.exe (outputs literal escape sequences)

Proposed fix

Either:

1. Use chalk or picocolors package (lightweight, handles detection)
2. Check process.stdout.isTTY and FORCE_COLOR / NO_COLOR env vars
3. At minimum, respect the NO_COLOR env var standard (https://no-color.org/)

Acceptance criteria

• Colors work on macOS/Linux
• Colors work on Windows Terminal / PowerShell 7
• Colors disabled gracefully on cmd.exe or when NO_COLOR is set
• CI output doesn't contain raw ANSI codes

[that-github-user]

Fixed in #45. Replaced hand-rolled ANSI escape codes with picocolors (2.6KB, zero deps). Automatically detects color support: TTY, NO_COLOR env var, Windows cmd.exe. Also fixed the "Next steps" section to show correct thinktank apply commands.