feat(files): add file storage subsystem with scenario and run artifact support

- add FileEntity, ScenarioFileEntity, ScenarioRunFileEntity with UUID-sharded disk tree
- FileStorageService: write/sha256/expiry, paginated listing, dynamic cleanup cron via SchedulerRegistry
- expose getScenarioFiles() and downloadFile() on ScriptContext for use in exec code
- wire scenarioId, runId, fileService into ExecContextBuilder and scenario scheduler
- add file upload and listing endpoints to ScenarioController
- add FILES_DIR, FILE_RUN_EXPIRATION_DAYS, FILE_CLEANUP_CRON to AppConfig

server/test/app.harness.ts

@@ -48,6 +48,9 @@ import { HealthController } from "../src/health/health.controller";
 import { HttpExceptionFilter } from "../src/filters/http-exception.filter";
 import { LoggingInterceptor } from "../src/interceptors/logging.interceptor";
 import { validateAppConfig } from "../src/config/app.config";
+import { FileEntity } from "../src/file/file.entity";
+import { ScenarioFileEntity } from "../src/file/scenario-file.entity";
+import { ScenarioRunFileEntity } from "../src/file/scenario-run-file.entity";
 
 export async function buildTestApp(): Promise<INestApplication> {
   const module: TestingModule = await Test.createTestingModule({
@@ -71,6 +74,9 @@ export async function buildTestApp(): Promise<INestApplication> {
           ScenarioCredentialEntity,
           CredentialEntity,
           SnippetEntity,
+          FileEntity,
+          ScenarioFileEntity,
+          ScenarioRunFileEntity,
         ],
         synchronize: true,
       }),