deploy: mount app/ + alembic from host in base compose

Lets a plain \`docker compose restart app\` pick up code edits without
an image rebuild. Image still bakes a copy at build time as a fallback.
Note: base compose is applied in prod too, so this affects the live
deploy — intentional, since this host edits live.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

docker-compose.yml

@@ -43,6 +43,12 @@ services:
       REDIS_URL: redis://redis:6379/0
     volumes:
       - ./config:/app/config:ro
+      # Mount app code + migrations from the host so edits take effect
+      # on a plain `docker compose restart app` — no image rebuild.
+      # Image still bakes a copy at build time as a fallback.
+      - ./app:/app/app
+      - ./alembic:/app/alembic
+      - ./alembic.ini:/app/alembic.ini:ro
     depends_on:
       db:
         condition: service_healthy
@@ -62,6 +68,9 @@ services:
       REDIS_URL: redis://redis:6379/0
     volumes:
       - ./config:/app/config:ro
+      - ./app:/app/app
+      - ./alembic:/app/alembic
+      - ./alembic.ini:/app/alembic.ini:ro
     depends_on:
       db:
         condition: service_healthy