Resolve OpenRouter native contract and promote secrets-engine PDP

Assistant: codex
Assistant-Model: gpt-6-astra
Assistant-Session: 01a09cbb-87c6-7900-a145-4ce53ba9f1a6

internal/callerauth/openrouter_test.go

@@ -0,0 +1,43 @@
+package callerauth
+
+import (
+	"context"
+	"errors"
+	"testing"
+)
+
+// IR-WP-0004 / WARDEN-WP-0039: a caller binding is representation,
+// not delegated authority over another system's credentials.
+func TestOpenRouterNativeCallerBoundary(t *testing.T) {
+	bindings := map[string]string{
+		"ops-warden":     "system:serviceaccount:ops-warden:ops-warden",
+		"secrets-engine": "system:serviceaccount:secrets-engine:secrets-engine",
+	}
+	for _, tc := range []struct {
+		name, caller string
+		systems      []string
+		denied       bool
+	}{
+		{"native lifecycle caller", bindings["secrets-engine"], []string{"secrets-engine"}, false},
+		{"warden own system", bindings["ops-warden"], []string{"ops-warden"}, false},
+		{"warden cannot represent custody owner", bindings["ops-warden"], []string{"railiance-platform"}, true},
+		{"warden cannot impersonate native engine", bindings["ops-warden"], []string{"secrets-engine"}, true},
+		{"radar is recipient not lifecycle caller", "system:serviceaccount:intelligence-radar:intelligence-radar", []string{"secrets-engine"}, true},
+		{"native caller cannot represent custody owner", bindings["secrets-engine"], []string{"railiance-platform"}, true},
+		{"batch must bind every owner", bindings["ops-warden"], []string{"ops-warden", "railiance-platform"}, true},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			auth, err := New(ModeEnforce, fakeReviewer{identity: Identity{Username: tc.caller, Audiences: []string{"flex-auth"}}}, "flex-auth", bindings, nil)
+			if err != nil {
+				t.Fatal(err)
+			}
+			err = auth.Authorize(context.Background(), "Bearer synthetic-caller", tc.systems)
+			if tc.denied && !errors.Is(err, ErrForbidden) {
+				t.Fatalf("want forbidden, got %v", err)
+			}
+			if !tc.denied && err != nil {
+				t.Fatal(err)
+			}
+		})
+	}
+}