fix(api): import AuthModule in CredentialsModule for DI resolution

CredentialsController uses AuthGuard which depends on AuthService.
NestJS resolves guard dependencies in the module context, so
CredentialsModule needs to import AuthModule directly.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/api/src/credentials/credentials.module.ts

@@ -2,11 +2,12 @@ import { Module } from "@nestjs/common";
 import { CredentialsController } from "./credentials.controller";
 import { CredentialsService } from "./credentials.service";
 import { PrismaModule } from "../prisma/prisma.module";
+import { AuthModule } from "../auth/auth.module";
 import { ActivityModule } from "../activity/activity.module";
 import { VaultModule } from "../vault/vault.module";
 
 @Module({
-  imports: [PrismaModule, ActivityModule, VaultModule],
+  imports: [PrismaModule, AuthModule, ActivityModule, VaultModule],
   controllers: [CredentialsController],
   providers: [CredentialsService],
   exports: [CredentialsService],