feat(pm-agent): the kubelet's pull credential, and the seventh field admission had not read

The registry had two blockers. #59 fixed the first (nodes resolved the hostname to the
non-hairpinned WAN and failed TLS against the router's CN=%D cert). This is the second:
the pull is unauthenticated, and this registry refuses unauthenticated clients outright —
measured 2026-10-05, its anonymous token carries access: null and every path 401s.

pm-agent-registry is a dockerconfigjson Secret (SOPS, placeholders) referenced by
imagePullSecrets on the dispatcher Deployment and on the committed worker Job template. It
holds the SAME Gitea token as pm-agent-credentials, because the two consumers need two
formats: the application reads a raw token from env, the kubelet reads a dockerconfigjson
before any container starts. Same one-value-in-two-files pattern as the Keycloak client
secret, documented in both .example files. The operator's part is the value plus one new
scope: read:package.

ADMISSION GAINED A SEVENTH RULE. imagePullSecrets is a pod-spec field no container
references, which is exactly why it is easy to leave unread — the same shape of omission
as initContainers, ephemeralContainers, env and envFrom before it. The kubelet reads the
named Secret, in this namespace, before anything runs. Rule 1's pattern now REQUIRES the
committed entry; rule 7 forbids any other and any second one. Both halves are needed: a
foreach over an absent list yields no result.

The leverage is small and the policy says so: the image is digest-pinned, so a different
pull credential cannot change WHAT runs. Pinned anyway — 'only the committed shape' is the
premise, and the rule costs four lines.

kyverno test: 33 passed, 0 failed (was 28). Three new fixtures, each a real path: the
committed entry plus a second one, a different Secret, and none at all.

The gate also caught me shipping the Secret in plaintext — I never ran sops -e -i on the
placeholder. Recorded in the handoff entry, because the file looked finished.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>

docs/plans/pm-agent-issue-to-pr.md

@@ -241,10 +241,11 @@ about runtime behaviour in this document is a design claim, not a measurement.
    `gitea.{{ k3s_base_domain }}` to the Gateway VIP in `node_baseline_hosts_pins`, the same
    pin the Keycloak issuer already carries, applied by
    `ansible-playbook playbooks/node-baseline.yml -e k3s_hosts=k3s_prod --tags hosts`;
-   (ii) the pull is still unauthenticated and no `imagePullSecret` exists in the tree — with
-   the credential decision now being local Gitea accounts with PATs, that means a
-   `dockerconfigjson` for an account whose token carries `read:package`. Only then does the
-   digest matter. Operator runs `infra/agent/build-image.sh`, pushes, and one PR replaces both
+   (ii) the pull must be authenticated — **now wired**: `pm-agent-registry`
+   (`dockerconfigjson`) is referenced by the Deployment and the committed worker Job
+   template, and the admission policy pins `imagePullSecrets` to exactly that name. The
+   operator supplies the value, from a Gitea token that also carries `read:package`. Only
+   then does the digest matter. Operator runs `infra/agent/build-image.sh`, pushes, and one PR replaces both
    placeholder digests. Expect the build itself to need iteration too: the nodejs module
    stream and the npm install have never run against this base. The same two blockers sit in
    front of `conformance-runner`, which shares the registry path and has never been pulled.