Go Ecosystem

Part of src/cmds/ — see also docs/contributing/TECHNICAL.md

Specifics

• go_cmd.rs uses GoCommands sub-enum in main.rs (same pattern as git/cargo)
• go test outputs NDJSON (-json flag injected by RTK) -- parsed line-by-line as streaming events
• golangci_cmd.rs forces --out-format=json for structured parsing