🐛 fix(mana-core-auth): add ConfigModule import to AiModule

Fixes NestJS dependency injection error where AiService couldn't
resolve ConfigService dependency.

Error:
> Nest can't resolve dependencies of the AiService (?).
> Please make sure that the argument Function at index [0] is available

Root cause: AiModule was missing ConfigModule in its imports array,
but AiService constructor requires ConfigService to read ai.geminiApiKey.

This was preventing mana-core-auth from starting in staging deployment.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

services/mana-core-auth/src/ai/ai.module.ts

@@ -1,8 +1,10 @@
 import { Module, Global } from '@nestjs/common';
+import { ConfigModule } from '@nestjs/config';
 import { AiService } from './ai.service';
 
 @Global()
 @Module({
+	imports: [ConfigModule],
 	providers: [AiService],
 	exports: [AiService],
 })