feat(multiplayer): expose server shutdown acknowledgement

server/store/server_shutdown_sql_test.go

@@ -0,0 +1,43 @@
+package store
+
+import (
+	"context"
+	"database/sql"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/cosmic-clash/cosmic-clash/server/domain"
+)
+
+func TestServerShutdownSQLUsesIdempotencyLockAndAudit(t *testing.T) {
+	checks := map[string][]string{
+		"insert": {"idempotency_keys", "ON CONFLICT (scope, idempotency_key) DO NOTHING", "payload_digest"},
+		"select": {"scope = $1", "idempotency_key = $2", "FOR UPDATE"},
+		"match":  {"match_id = $1", "server_id = $2", "FOR UPDATE"},
+		"audit":  {"SERVER_SHUTDOWN", "request_id", "metadata"},
+	}
+	queries := map[string]string{"insert": ServerShutdownIdempotencyInsertSQL, "select": ServerShutdownIdempotencySelectSQL, "match": ServerShutdownMatchLockSQL, "audit": ServerShutdownAuditSQL}
+	for name, fragments := range checks {
+		for _, fragment := range fragments {
+			if !strings.Contains(queries[name], fragment) {
+				t.Fatalf("%s query missing %q: %s", name, fragment, queries[name])
+			}
+		}
+	}
+}
+
+func TestRecordServerShutdownRejectsInvalidArguments(t *testing.T) {
+	binding := domain.WorkloadBinding{MatchID: "match-1", ServerID: "server-1"}
+	now := time.Unix(1000, 0).UTC()
+	for name, values := range map[string][2]string{
+		"missing reason": {"", "shutdown-key-123456"},
+		"short key":      {"planned", "short"},
+	} {
+		t.Run(name, func(t *testing.T) {
+			if err := RecordServerShutdown(context.Background(), (*sql.DB)(nil), binding, values[0], values[1], now); err == nil {
+				t.Fatal("expected validation error")
+			}
+		})
+	}
+}