Modernize: dig (DNS lookup)

[martinciu]

Evaluate replacing vanilla dig with a modern alternative.

Candidates (re-evaluate at decision time)

• doggo — colored DNS lookups, JSON output, friendly defaults
• dog — similar concept, slightly different UX

Decide

• Pick one based on output format and DoH/DoT support needs.
• If adopted: add to Brewfile, update CLAUDE.md and shell-colors cheatsheet.

Out of scope

• Don't bundle multiple tool swaps into one PR.