feat(api): per-license API key management + roadmap sync

API keys (roadmap: 'API key management per license'):
- migration 023_api_keys; ApiKey entity; ApiKeysModule (@Global, exports
  ApiKeysService) wired into app.module.
- Service: create (corr_<prefix>_<secret>, returns plaintext once, stores
  sha256 hash + prefix), list (no hash), revoke, and validateKey(rawKey) ->
  { license_id } for a future API-key auth guard. Controller license-scoped +
  RBAC (apikeys.view/manage).

Roadmap: moved the shipped multi-game items (multi-instance host runtime,
per-game wipe + event scheduling) into a 'Phase 2 — Multi-game runtime' shipped
group; Dune/Conan/Soulmask Formulae stay in-progress.

Backend tsc + frontend build green. Migration applies on a fresh DB (Saturday host).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend-nest/src/modules/api-keys/dto/create-api-key.dto.ts

@@ -0,0 +1,10 @@
+import { IsString, IsNotEmpty, MaxLength } from 'class-validator';
+import { ApiProperty } from '@nestjs/swagger';
+
+export class CreateApiKeyDto {
+  @ApiProperty({ description: 'Human-readable label for this key', maxLength: 100 })
+  @IsString()
+  @IsNotEmpty()
+  @MaxLength(100)
+  name: string;
+}