diff --git a/CLAUDE.md b/CLAUDE.md
index ffdf827..9e545e9 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -65,8 +65,11 @@ npm test                             # all Playwright specs (build first!)
 npx playwright test <tool>           # one spec
 ./dev-server start  # stop           # cache-busting HTTP on :8000
 
-# zddc/ Go server (sub-project)
-(cd zddc && go test ./...)           # unit tests (Go 1.24+)
+# zddc/ Go server (sub-project). Go is NOT on the host — run go test/build
+# through the localhost/zddc-go:1.24 container (canonical wrapper, with the
+# GOPROXY/GOPRIVATE env it needs, in AGENTS.md § Test). The bare command
+# below fails on the host.
+(cd zddc && go test ./...)           # unit tests (Go 1.24+) — via the podman wrapper, not host
 ```
 
 No lint/typecheck/format commands exist for the HTML tools — vanilla JS + POSIX sh by design.