chore(memoro): remove old NestJS backends (Phase 8+9)

Delete apps/memoro/apps/backend/ (NestJS) and apps/memoro/apps/audio-backend/
(NestJS) — all functionality has been ported to the new Hono/Bun servers
(apps/server/ and apps/audio-server/).

Also clean up root and memoro package.json scripts to remove references
to the old @memoro/backend and @memoro/audio-backend packages.

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

packages/manadeck-database/docker-compose.yml

@@ -1,39 +0,0 @@
-services:
-  postgres:
-    image: postgres:16-alpine
-    container_name: manadeck-postgres
-    restart: unless-stopped
-    environment:
-      POSTGRES_USER: manadeck
-      POSTGRES_PASSWORD: manadeck_dev_password
-      POSTGRES_DB: manadeck
-    ports:
-      - "5433:5432"
-    volumes:
-      - manadeck_postgres_data:/var/lib/postgresql/data
-    healthcheck:
-      test: ["CMD-SHELL", "pg_isready -U manadeck -d manadeck"]
-      interval: 10s
-      timeout: 5s
-      retries: 5
-
-  # Optional: pgAdmin for database management UI
-  pgadmin:
-    image: dpage/pgadmin4:latest
-    container_name: manadeck-pgadmin
-    restart: unless-stopped
-    environment:
-      PGADMIN_DEFAULT_EMAIL: admin@manadeck.local
-      PGADMIN_DEFAULT_PASSWORD: admin
-      PGADMIN_CONFIG_SERVER_MODE: 'False'
-    ports:
-      - "5050:80"
-    volumes:
-      - manadeck_pgadmin_data:/var/lib/pgadmin
-    depends_on:
-      postgres:
-        condition: service_healthy
-
-volumes:
-  manadeck_postgres_data:
-  manadeck_pgadmin_data: