chore: DevKit conformance audit — minor improvements

[HerbHall]

DevKit Conformance Audit (2026-03-04)

Score: 95% — excellent

CLI-Play has near-perfect DevKit conformance.

Minor Improvements

• golangci-lint invocation — pre-push hook and Makefile use bare golangci-lint command instead of go run github.com/golangci/golangci-lint/v2/cmd/golangci-lint@v2.10.1 (see DevKit AP#91, KG#60)
• No nightly build workflow — optional for CLI tools
• No release gate workflow — optional

What's Working

Everything else: CLAUDE.md, CI, pre-push hook, .golangci.yml v2, Makefile, .editorconfig (root=false), release-please, LICENSE, VERSION, .gitignore.