feat(api): fleet data model Phase A — License -> Host -> Instance

Migration 022 adds agent_hosts / game_instances / instance_clusters /
instance_stats (named agent_hosts to avoid the existing B2B hosts
table). HostAgentConsumerService now parses the full v2 heartbeat and
upserts an agent_hosts row (host metrics: cpu/mem/disk/agent version,
keyed by license_id+hostname until enrollment) plus one game_instances
row per heartbeat instance entry (state + uptime, the billing unit).
Legacy server_connections write retained so the current panel keeps
working — additive migration, nothing breaks. Staleness sweep + offline
beacon now flip agent_hosts too. cluster_id FK reserved for Soulmask/
Dune. Migration applied to live DB; tsc green.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

backend-nest/src/app.module.ts

@@ -52,6 +52,8 @@ import { NatsBridgeService } from './services/nats-bridge.service';
 import { HostAgentConsumerService } from './services/host-agent-consumer.service';
 import { ServerConnection } from './entities/server-connection.entity';
 import { License } from './entities/license.entity';
+import { AgentHost } from './entities/agent-host.entity';
+import { GameInstance } from './entities/game-instance.entity';
 import { SteamService } from './services/steam.service';
 
 // Gateway
@@ -95,7 +97,7 @@ import { NatsBridgeGateway } from './gateways/nats-bridge.gateway';
     ScheduleModule.forRoot(),
 
     // Repositories for app-level shared services (host-agent consumer)
-    TypeOrmModule.forFeature([ServerConnection, License]),
+    TypeOrmModule.forFeature([ServerConnection, License, AgentHost, GameInstance]),
 
     // Feature Modules
     AuthModule,