FastAPI microservice wrapping ByteDance/Dolphin-v2 (Qwen2.5-VL-3B base)
for structured document extraction. Exposes POST /extract and GET /health.
Maps Dolphin's 21 element types to cf-core's 7-type canonical schema.
Services: cf-text /extract, /health
Env vars: CF_DOCUVISION_MODEL, CF_DOCUVISION_DEVICE, CF_DOCUVISION_PORT
GPU: 8GB+ VRAM required for Dolphin-v2; CPU fallback available but very slow.
