feat!(): add custom execution context

sample/common/guards/admin.guard.ts

@@ -0,0 +1,21 @@
+import { CanActivate, ExecutionContext, Injectable } from '@nestjs/common';
+import { TelegrafExecutionContext } from '../../../lib/execution-context/telegraf-execution-context';
+import { Context } from '../../interfaces/context.interface';
+import { TelegrafException } from '../../../lib/errors';
+
+@Injectable()
+export class AdminGuard implements CanActivate {
+  private readonly ADMIN_IDS = [];
+
+  canActivate(context: ExecutionContext): boolean {
+    const ctx = TelegrafExecutionContext.create(context);
+    const { from } = ctx.getContext<Context>();
+
+    const isAdmin = this.ADMIN_IDS.includes(from.id);
+    if (!isAdmin) {
+      throw new TelegrafException('You are not admin >:(');
+    }
+
+    return true;
+  }
+}