feat: P1 profile/portrait API and freeze local-dev environment

Add host-first environment contracts (Local vs CI vs Prod), deps-only
compose, and the Profile → Portrait → deep-access mock payment slice
with device identity and auto-migrate on API startup.

Co-authored-by: Cursor <cursoragent@cursor.com>

deploy/docker-compose.yml

@@ -1,3 +1,9 @@
+# Compatibility alias for local dependency services.
+# Prefer from repo root:
+#   docker compose -f docker-compose.dev.yml up -d
+#
+# Does NOT run api or user-h5. Policy: .ai/docker.md
+
 services:
   postgres:
     image: postgres:16-alpine
@@ -9,7 +15,12 @@ services:
     ports:
       - "5432:5432"
     volumes:
-      - yuxingu_pg:/var/lib/postgresql/data
+      - yuxingu_pg_dev:/var/lib/postgresql/data
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U yuxingu -d yuxingu"]
+      interval: 5s
+      timeout: 5s
+      retries: 10
 
 volumes:
-  yuxingu_pg:
+  yuxingu_pg_dev: