Add Docker support and refactor prompt/queue internals

- Add Dockerfile, docker-compose.yml, .dockerignore for containerised deployment
- Extract _resolve_character(), _ensure_character_fields(), _append_background() helpers to eliminate repeated inline character-field injection and background-tag patterns across all secondary-category generate routes
- Add _IDENTITY_KEYS / _WARDROBE_KEYS constants
- Fix build_extras_prompt() bug: detailer prompt (a list) was being appended as a single item instead of extended
- Replace all per-route _finalize closures with _make_finalize() factory, reducing duplication across 10 generate routes
- Add _prune_job_history() called each worker loop iteration to prevent unbounded memory growth
- Remove 10 orphaned legacy finalize_generation HTTP routes and check_status route (superseded by job queue API since job-queue branch)
- Remove one-time migration scripts (migrate_actions, migrate_detailers, migrate_lora_weight_range, migrate_wardrobe)
- Update CLAUDE.md and README.md to document new helpers, queue architecture, and Docker deployment

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

docker-compose.yml

@@ -0,0 +1,31 @@
+services:
+  danbooru-mcp:
+    build: https://git.liveaodh.com/aodhan/danbooru-mcp.git
+    image: danbooru-mcp:latest
+    stdin_open: true
+    restart: unless-stopped
+
+  app:
+    build: .
+    ports:
+      - "5782:5000"
+    environment:
+      # ComfyUI runs on the Docker host
+      COMFYUI_URL: http://10.0.0.200:8188     # Compose manages danbooru-mcp — skip the app's auto-start logic
+      SKIP_MCP_AUTOSTART: "true"
+    volumes:
+      # Persistent data
+      - ./data:/app/data
+      - ./static/uploads:/app/static/uploads
+      - ./instance:/app/instance
+      - ./flask_session:/app/flask_session
+      # Model files (read-only — used for checkpoint/LoRA scanning)
+      - /Volumes/ImageModels:/ImageModels:ro
+      # Docker socket so the app can run danbooru-mcp tool containers
+      - /var/run/docker.sock:/var/run/docker.sock
+    extra_hosts:
+      # Resolve host.docker.internal on Linux hosts
+      - "host.docker.internal:host-gateway"
+    depends_on:
+      - danbooru-mcp
+    restart: unless-stopped