feat(deploy): consolidated dev stack with auto-provisioned Zitadel

Single docker-compose stack for local development (Postgres, Zitadel,
RabbitMQ, SeaweedFS + bucket init, Jaeger) plus an optional overlay to run
the .NET apps in Docker. up.ps1 orchestrates the full bootstrap: stack up,
stream-ticket keys, EF Core migrations and Zitadel provisioning.

- Zitadel is provisioned automatically (service-account PAT -> project +
  OIDC app with JWT access token); the generated ClientId is wired into
  Musify.Api user-secrets and .env. No manual console steps.
- ZITADEL_EXTERNAL_DOMAIN=host.docker.internal so token validation works
  both with local apps and full-docker.
- App Dockerfiles copy AppSettings*.json to lowercase so config loads on
  case-sensitive Linux; Worker image ships ffmpeg.
- Scripts split by responsibility (common/stream-keys/migrate/provision);
  apps overlay de-duped via YAML anchors.
- Remove the superseded standalone seaweedfs compose; point docs/development
  at the unified stack.

deploy/seaweedfs/docker-compose.yml

@@ -1,32 +0,0 @@
-services:
-  seaweedfs:
-    image: chrislusf/seaweedfs:latest
-    container_name: seaweedfs
-    # All-in-one dev server: master + volume + filer + S3 gateway.
-    command: >
-      server
-      -ip.bind=0.0.0.0
-      -dir=/data
-      -master.volumeSizeLimitMB=1024
-      -volume.max=0
-      -filer
-      -s3
-      -s3.config=/etc/seaweedfs/s3.conf
-    ports:
-      - "9333:9333"   # master (admin/UI)
-      - "8888:8888"   # filer HTTP  -> used by the Media Gateway
-      - "8333:8333"   # S3 API      -> used by the WebApi (InfrastructureStorage:Address)
-      # Volume server (8080) is left unpublished on purpose: it only needs to be
-      # reachable internally, and 8080 clashes with Zitadel on the host.
-    volumes:
-      - seaweedfs_data:/data
-      - ./s3.conf:/etc/seaweedfs/s3.conf:ro
-    restart: unless-stopped
-    healthcheck:
-      test: ["CMD", "wget", "-q", "-O", "-", "http://localhost:9333/cluster/healthz"]
-      interval: 10s
-      timeout: 5s
-      retries: 10
-
-volumes:
-  seaweedfs_data: