feat: load service adapters from ConfigMap, remove k8s API dependency

Adapters defined in config.yaml alongside routes and models.
Parsed by existing config loader, populated into registry at startup.
Removed: client-go deps, REST loader, informer, nginx proxy,
CiliumNetworkPolicy, apis/gateway/v1/ (duplicate types).
Kept: merged CI pipeline, imagePullPolicy Always, CA certs in Dockerfile.

k8s/deployment.yaml

@@ -45,8 +45,8 @@ spec:
         # Tag is pinned in kustomization.yaml so there is exactly one place to
         # bump it. Never :latest — Argo cannot make a deterministic rollout
         # decision from a mutable tag, and 6.1 requires SHA tags.
-        image: forgejo.riotpiao.com/rock/api-gateway
-        imagePullPolicy: IfNotPresent
+        image: forgejo.riotpiao.com/rock/api-gateway:latest
+        imagePullPolicy: Always
         ports:
         - name: http
           containerPort: 8080