chore(compose): use DaoCloud mirror for base images in prod/dev

Made-with: Cursor

docker-compose.prod.yml

@@ -1,6 +1,9 @@
 # Production stack for the current codebase: FastAPI + PostgreSQL.
 # The API hard-fails on startup if the database is not reachable, so DB health is required.
 #
+# Base images use DaoCloud public mirror (大陆可访问): docker.io → docker.m.daocloud.io
+# See https://github.com/DaoCloud/public-image-mirror
+#
 # Published API port defaults to 38080 on the host (override with API_PORT).
 #
 # GPU (NVIDIA) inference: uv.lock pins torch/torchvision from the PyTorch *CPU* index (see pyproject.toml).
@@ -8,7 +11,7 @@
 # and assign GPUs to the api service (deploy.resources.reservations.devices).
 services:
   db:
-    image: postgres:16-alpine
+    image: docker.m.daocloud.io/library/postgres:16-alpine
     environment:
       POSTGRES_USER: ${POSTGRES_USER:-postgres}
       POSTGRES_PASSWORD: ${POSTGRES_PASSWORD:?Set POSTGRES_PASSWORD}