feat: add linked mock data seeding CLI

backend/api/internal/seed/mock_test.go

@@ -0,0 +1,41 @@
+package seed
+
+import (
+	"regexp"
+	"testing"
+)
+
+func TestMockEntityIdentitiesAreStableAndUnique(t *testing.T) {
+	identityPattern := regexp.MustCompile(
+		`^00000000-0000-7000-8000-[0-9]{12}$`,
+	)
+	seen := make(map[string]struct{}, 46)
+	for sequence := 1; sequence <= 46; sequence++ {
+		record := entity(sequence, "enabled")
+		if !identityPattern.MatchString(record.Identity) {
+			t.Fatalf("entity(%d) identity = %q", sequence, record.Identity)
+		}
+		if _, exists := seen[record.Identity]; exists {
+			t.Fatalf("duplicate identity %q", record.Identity)
+		}
+		seen[record.Identity] = struct{}{}
+		if record.Status != "enabled" || record.Version != 1 {
+			t.Fatalf("entity(%d) has unexpected defaults: %#v", sequence, record)
+		}
+	}
+}
+
+func TestIdentityOfEmbeddedEntity(t *testing.T) {
+	record := struct {
+		Entity struct {
+			Identity string
+		}
+	}{}
+	record.Entity.Identity = "mock-identity"
+	if got := identityOf(&record); got != record.Entity.Identity {
+		t.Fatalf("identityOf() = %q, want %q", got, record.Entity.Identity)
+	}
+	if got := identityOf(nil); got != "" {
+		t.Fatalf("identityOf(nil) = %q, want empty", got)
+	}
+}