feat: add global system notices and Beijing order time display

internal/store/time_integration_test.go

@@ -0,0 +1,48 @@
+package store
+
+import (
+	"os"
+	"testing"
+
+	"github.com/jmoiron/sqlx"
+)
+
+func TestOrderCreatedTimeRespectsDatabaseSessionZone(t *testing.T) {
+	dsn := os.Getenv("OLONS_TEST_MYSQL_DSN")
+	if dsn == "" {
+		t.Skip("set OLONS_TEST_MYSQL_DSN to run the time integration test")
+	}
+	db, err := sqlx.Connect("mysql", dsn)
+	if err != nil {
+		t.Fatal(err)
+	}
+	db.SetMaxOpenConns(1)
+	db.SetMaxIdleConns(1)
+	t.Cleanup(func() { _ = db.Close() })
+	if _, err := db.Exec(`CREATE TEMPORARY TABLE order_time_fixture (created_at DATETIME(3))`); err != nil {
+		t.Fatal(err)
+	}
+	for _, test := range []struct{ zone, wallTime string }{
+		{"+00:00", "2026-10-22 13:06:00"},
+		{"+08:00", "2026-10-22 21:06:00"},
+	} {
+		t.Run(test.zone, func(t *testing.T) {
+			if _, err := db.Exec(`SET SESSION time_zone=?`, test.zone); err != nil {
+				t.Fatal(err)
+			}
+			if _, err := db.Exec(`DELETE FROM order_time_fixture`); err != nil {
+				t.Fatal(err)
+			}
+			if _, err := db.Exec(`INSERT INTO order_time_fixture (created_at) VALUES (?)`, test.wallTime); err != nil {
+				t.Fatal(err)
+			}
+			var actual string
+			if err := db.Get(&actual, `SELECT `+databaseWallTimeUTC("created_at")+` FROM order_time_fixture`); err != nil {
+				t.Fatal(err)
+			}
+			if actual != "2026-10-22T13:06:00Z" {
+				t.Fatalf("normalized timestamp = %q, want 2026-10-22T13:06:00Z", actual)
+			}
+		})
+	}
+}