feat: wire HuntingController/HuntingModule and enrich current-location with monster pool

Registers HuntingModule (POST /api/hunts) into the DI graph alongside its
new entities, and adds possibleMonsters (enabled LocationMonster pool,
weight-descending, empty when hunting is disabled) to
WorldService.getCurrentLocation. Also updates the pre-existing
DB-less app.e2e-spec.ts to override HuntingModule the same way the other
feature modules already are, since it now needs a real DataSource.

apps/api/src/hunting/hunting.controller.ts

@@ -0,0 +1,13 @@
+import { Controller, Post } from '@nestjs/common';
+import { DEMO_CHARACTER_ID } from '../demo/demo-character.constants';
+import { HuntResultDto, HuntingService } from './hunting.service';
+
+@Controller('hunts')
+export class HuntingController {
+  constructor(private readonly huntingService: HuntingService) {}
+
+  @Post()
+  startHunt(): Promise<HuntResultDto> {
+    return this.huntingService.startHunt(DEMO_CHARACTER_ID);
+  }
+}