fix(gateway): anchor remaining config loads (#1138)

Co-Authored-By: Claude Haiku 4.5 <[email protected]>

apps/gateway/src/config/config.module.ts

@@ -1,5 +1,6 @@
 import { Global, Module } from '@nestjs/common';
 import { loadConfig, type MosaicConfig } from '@mosaicstack/config';
+import { resolveGatewayConfigPath } from '../env.js';
 
 export const MOSAIC_CONFIG = 'MOSAIC_CONFIG';
 
@@ -8,7 +9,7 @@ export const MOSAIC_CONFIG = 'MOSAIC_CONFIG';
   providers: [
     {
       provide: MOSAIC_CONFIG,
-      useFactory: (): MosaicConfig => loadConfig(),
+      useFactory: (): MosaicConfig => loadConfig(resolveGatewayConfigPath()),
     },
   ],
   exports: [MOSAIC_CONFIG],