feat: Wire execution engines for schedules, alerts, wipes, and module install

- schedules/: Add schedule executor in SchedulesService — polls every 60s for
  tasks where next_run <= now, dispatches NATS commands per task_type
  (restart, announcement, command, plugin_reload). Calculates next_run from
  cron expression on create/update/toggle. Bootstraps missing next_run values
  on startup. Wire NatsService into SchedulesModule.

- alerts/: Add alert evaluator in AlertsService — polls every 90s, loads all
  alert_config rows, queries latest server_stats per license, evaluates FPS
  degradation and population drop thresholds. Fires alert_history records on
  breach. Enforces 10-minute in-memory cooldown per alert type per license to
  prevent flooding. Wire ServerStats repo into AlertsModule.

- wipes/: Replace hardcoded dry-run mock with profile-aware simulation.
  Resolves actual WipeProfile by ID (cross-tenant protected), builds
  would_delete/would_preserve lists from wipe_type, factors pre_wipe_config
  (backup, countdown warnings) and post_wipe_config (health checks, retry
  attempts) into estimated_duration_seconds. Returns profile_name and notes.

- store/: Fix installModule stub — creates a real module_installations record
  with status='installed' and installed_at timestamp. Idempotent on retry,
  resets failed installations. Wire ModuleInstallation repo into StoreModule.
  getMyModules now returns real installation data instead of filtered purchases.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend-nest/src/modules/alerts/alerts.module.ts

@@ -4,9 +4,10 @@ import { AlertsController } from './alerts.controller';
 import { AlertsService } from './alerts.service';
 import { AlertConfig } from '../../entities/alert-config.entity';
 import { AlertHistory } from '../../entities/alert-history.entity';
+import { ServerStats } from '../../entities/server-stats.entity';
 
 @Module({
-  imports: [TypeOrmModule.forFeature([AlertConfig, AlertHistory])],
+  imports: [TypeOrmModule.forFeature([AlertConfig, AlertHistory, ServerStats])],
   controllers: [AlertsController],
   providers: [AlertsService],
   exports: [AlertsService],