Contacts cleanup

Read ../gog/SKILL.md and ../gog-contacts/SKILL.md first.

1. Detect duplicates without mutation:

``bash gog --account [email protected] --readonly contacts dedupe --match email,phone,name --json --wrap-untrusted ``

1. Present each proposed group with resource IDs and the fields that matched. Flag conflicts in

names, organizations, notes, and non-empty phone/email values.

1. Preview the exact merge plan:

``bash gog --account [email protected] contacts dedupe --resource people/ONE \ --resource people/TWO --apply --dry-run --json ``

1. Apply only explicitly approved groups. Omit --force unless the user requested non-interactive

execution after reviewing the plan.

Never merge solely on a similar name. Prefer exact normalized email or phone evidence and retain the richest contact as the primary resource.