fix(#1391): boot-time ValidationPipe metatype self-check — fail loud at startup (#1419)

Co-authored-by: code-infra-01 <[email protected]>

apps/gateway/src/main.ts

@@ -14,10 +14,16 @@ import { mountMcpHandler } from './mcp/mcp.controller.js';
 import { McpService } from './mcp/mcp.service.js';
 import { detectAndAssertTier, TierDetectionError } from '@mosaicstack/storage';
 import { resolveGatewayConfigPath } from './env.js';
+import { assertValidationPipeSeesDtoDecorators } from './validation-pipe-check.js';
 
 async function bootstrap(): Promise<void> {
   const logger = new Logger('Bootstrap');
 
+  // Fail loud BEFORE anything else if the global ValidationPipe cannot see
+  // the guarded DTOs' decorated properties (#1391): a broken metatype turns
+  // every request body into a 400 at first use; this surfaces it at boot.
+  assertValidationPipeSeesDtoDecorators();
+
   if (!process.env['BETTER_AUTH_SECRET']) {
     throw new Error('BETTER_AUTH_SECRET is required');
   }