store: tighten CHECK constraint on host_repo_stats.last_check_status

internal/store/store_test.go

@@ -138,6 +138,14 @@ func TestMigration0009Schema(t *testing.T) {
 	if lockPresent != 0 {
 		t.Errorf("expected lock_present=0, got %d", lockPresent)
 	}
+
+	// CHECK (last_check_status IN ('ok','errors_found','failed')) must reject
+	// an invalid value.
+	if _, err := s.DB().ExecContext(ctx,
+		`UPDATE host_repo_stats SET last_check_status = ? WHERE host_id = ?`,
+		"wat", "h-0009"); err == nil {
+		t.Fatal("expected CHECK constraint violation on last_check_status='wat', got nil")
+	}
 }
 
 func TestForeignKeysEnforced(t *testing.T) {