Skill: Go project conventions

Goal

Provide a standard Go workflow with module caching, linting, security checks, and tests driven by Make.

Make targets (recommended)

• •make deps → go mod download + install golangci-lint and gosec if missing
• •make vet → go vet ./...
• •make lint → golangci-lint run --timeout=5m
• •make security → gosec ./...
• •make test → go test -v -race -coverprofile=coverage.out ./...
• •make check → make vet && make lint