build(go.mod): retract the hawk-era v0.1.0–v0.2.0 tags

proxy.golang.org serves v0.1.0, v0.1.1 and v0.2.0 for
github.com/GrayCodeAI/rho, but those tags were cut before the rename:
their go.mod declares module github.com/GrayCodeAI/hawk and they contain
no cmd/rho, so `go install .../cmd/rho@latest` fails with "does not
contain package" and tooling (pkg.go.dev, dependabot) lists them as rho
versions. The proxy keeps them forever, so retract the range with a
rationale; retractions take effect from the first release that carries
this go.mod (v0.3.0), after which @latest is v0.3.0 and the old
versions are marked retracted.

`go mod tidy -diff`, `go mod verify` and the replace-directive guard
pass; a testaudit test keeps the range retracted and ensures VERSION is
never inside it.

Refs: F025

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: Patel230

go.mod

@@ -6,6 +6,7 @@ import (
 	"strings"
 	"testing"
 
+	"golang.org/x/mod/modfile"
 	"golang.org/x/mod/semver"
 )
 
@@ -36,3 +37,30 @@ func TestVersionFileIsSemVer(t *testing.T) {
 		t.Fatalf("VERSION = %q is below 0.3.0, the first rho-named release", v)
 	}
 }
+
+// The hawk-era tags v0.1.0, v0.1.1 and v0.2.0 are on the Go module proxy under
+// this module path but declare module github.com/GrayCodeAI/hawk; go.mod must
+// keep retracting them so `go list -m -versions` and tooling skip them.
+func TestGoModRetractsHawkEraVersions(t *testing.T) {
+	f, err := modfile.Parse("go.mod", readRepoFile(t, "go.mod"), nil)
+	if err != nil {
+		t.Fatalf("parse go.mod: %v", err)
+	}
+	for _, v := range []string{"v0.1.0", "v0.1.1", "v0.2.0"} {
+		retracted := false
+		for _, r := range f.Retract {
+			if semver.Compare(r.Low, v) <= 0 && semver.Compare(v, r.High) <= 0 {
+				retracted = true
+			}
+		}
+		if !retracted {
+			t.Errorf("go.mod does not retract hawk-era %s", v)
+		}
+	}
+	current := "v" + repoVersion(t)
+	for _, r := range f.Retract {
+		if semver.Compare(r.Low, current) <= 0 && semver.Compare(current, r.High) <= 0 {
+			t.Errorf("go.mod retracts the current VERSION %s", current)
+		}
+	}
+}