Add token expiry and Telegram notification features

- Introduced `STANDX_TOKEN_EXPIRY` configuration to manage token expiration, including handling logic for active, expired, and silent states.
- Implemented Telegram notifications for key events such as order filled, position opened/closed, stop loss triggered, and token expiration.
- Updated Maker Points engine to integrate token expiry checks and notification sending, enhancing user awareness of trading conditions.
- Enhanced documentation to include details on configuring token expiry and Telegram notifications for improved user guidance.

src/notifications/types.ts

@@ -0,0 +1,22 @@
+export type NotificationLevel = "info" | "warn" | "error" | "success";
+
+export interface TradeNotification {
+  type: "order_filled" | "position_opened" | "position_closed" | "stop_loss" | "token_expired" | "custom";
+  level: NotificationLevel;
+  symbol: string;
+  title: string;
+  message: string;
+  accountLabel?: string;
+  details?: Record<string, string | number | boolean | null>;
+  timestamp?: number;
+}
+
+export interface NotificationSender {
+  send(notification: TradeNotification): Promise<void>;
+  isEnabled(): boolean;
+}
+
+export interface NotificationConfig {
+  enabled: boolean;
+  accountLabel?: string;
+}