fix(ci): gate image build on asyncpg and disable DinD layer cache

The main-f9f0091 Forgejo image shipped with an empty venv (0-byte
requirements.txt). Add Dockerfile RUN verification, --no-cache on CI
build, and a post-build import smoke test before push.

deploy/railiance/apps/helm/state-hub-values.yaml

@@ -5,7 +5,8 @@ namespace:
   create: false
 
 image:
-  tag: "f2e042a"
+  repository: forgejo.coulomb.social/coulomb/state-hub
+  tag: "main-f9f0091"
 
 ingress:
   enabled: false