feat(pm-agent): pin the first published agent-runner digest, start dry, and fix the token scopes

Rebased #61 onto the CI image pipeline (#81). This commit makes the remaining in-git
blockers to going live go away:

- deployment.yaml and PM_WORKER_IMAGE pin images run 340's digest (sha256:c4eba5b3...,
  tag sha-523cd9118f95 = main), read from the registry. Renovate markers unchanged.
- PM_DRY_RUN=true and PM_REQUIRE_LABEL=agent for the first run. Dry run is required, not
  just cautious: the run-340 image's baked worker template predates imagePullSecrets, so
  admission would deny its Jobs until CI re-publishes after this merge and Renovate bumps.
- Token scopes: Gitea 1.24.3 scopes GET /api/v1/user (the dispatcher's first call) under
  read:user. The documented list was missing it. Now read:user, write:repository,
  write:issue, read:package everywhere.
- Org-package read documented as a team (Packages=Read, no repos), not just a scope.
- sops is toolbox-only; the .examples say so and give the in-place edit.
- runbook: key-name check no longer emits Secret values before the pipe.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

platform/pm-agent/deployment.yaml

@@ -48,7 +48,7 @@ spec:
         # It is a hand-maintained marker rather than a computed hash because Flux's
         # Kustomization here does not run a configmap generator; bump it in the same commit
         # as a change to configmap.yaml.
-        pm-agent.homelab.keithjackson.dev/config-generation: "1"
+        pm-agent.homelab.keithjackson.dev/config-generation: "2"
     spec:
       serviceAccountName: pm-agent
       # The kubelet's credential for pulling this image. Not the agent's Gitea credential —
@@ -73,10 +73,12 @@ spec:
           # disagree about the shape the admission policy enforces. Replaced together, in ONE
           # Renovate pull request: both lines carry the same marker, so Renovate treats them as
           # one dependency and bumps them in the same branch. The digest comes from CI's publish
-          # of agent-runner's `main` tag (.gitea/workflows/images.yaml) — the all-zero
-          # placeholder below is impossible on purpose (see configmap.yaml PM_WORKER_IMAGE).
+          # of agent-runner's `main` tag (.gitea/workflows/images.yaml). The value below is the
+          # FIRST publish (images run 340, tag sha-523cd9118f95 = main at the time), read from
+          # the registry's manifest endpoint on 2026-10-30 and pinned by hand once so the
+          # dispatcher does not wait on Renovate's first run; every later bump is Renovate's.
           # renovate-digest: image=gitea.home.keithjackson.dev/home-network/agent-runner tag=main
-          image: gitea.home.keithjackson.dev/home-network/agent-runner@sha256:0000000000000000000000000000000000000000000000000000000000000000
+          image: gitea.home.keithjackson.dev/home-network/agent-runner@sha256:c4eba5b3c508bf456a03391ac76f8275e7ea28a829da1450d99f6f6f25c6eb42
           imagePullPolicy: IfNotPresent
           command:
             - /usr/local/bin/pm-dispatch