Setup nulfrog Skills

A thin overlay on top of setup-matt-pocock-skills. The base skill stays pristine (in sync with upstream mattpocock/skills); this skill layers on the local-only conventions this repo has adopted.

Run the base skill first. Run /setup-matt-pocock-skills to scaffold the issue tracker, triage labels, and domain docs. Then run this skill to apply the overrides and additions below.

Overrides to the base skill

Explore step: also check the CLAUDE.md / AGENTS.md relationship

In addition to the base skill's "Explore" checks, when inspecting AGENTS.md and CLAUDE.md: does CLAUDE.md import AGENTS.md (@AGENTS.md), or does it hold content directly?

Write step: AGENTS.md is canonical, CLAUDE.md is a pointer

This replaces the base skill's "Pick the file to edit" logic (which edits whichever of CLAUDE.md / AGENTS.md already exists). Instead:

Put the content in AGENTS.md, and point CLAUDE.md at it. AGENTS.md is the canonical file, holding both the ## Communication style and ## Agent skills sections go there. CLAUDE.md stays a thin pointer that imports it, so Claude Code reads the same source as every other agent.