feat: let the runner build and the cluster pull from the Forgejo registry

- Runner egress: allow 192.168.1.160/32:443. forgejo.riotpiao.com resolves to
  the ingress LB, inside the 192.168.1.0/24 block the NetworkPolicy denies, so
  docker push hung until timeout.
- dind CA: also mount homelab-ca at /etc/docker/certs.d/forgejo.riotpiao.com/,
  the path dockerd actually reads for per-registry trust.
- Pull secret: dockerconfigjson for the api namespace; /v2/ answers 401.
- AppProject: allow the Forgejo repo as a source for api-gw.

k8s/infra/forgejo-runner/templates/deployment.yaml

@@ -91,6 +91,13 @@ spec:
             - name: homelab-ca
               mountPath: /etc/ssl/certs/homelab-ca.pem
               subPath: ca.crt
+            # dockerd resolves per-registry CAs from /etc/docker/certs.d/<host>/
+            # before falling back to the system pool. Mounting it here is what
+            # makes `docker push forgejo.riotpiao.com/...` trust the homelab CA
+            # rather than failing x509: signed by unknown authority.
+            - name: homelab-ca
+              mountPath: /etc/docker/certs.d/forgejo.riotpiao.com/ca.crt
+              subPath: ca.crt
           resources:
             {{- toYaml .Values.dind.resources | nindent 12 }}