docs: correct CI/platform documentation that was stale, wrong, or load-bearing

The 2026-09-29 session found the merge gate did not exist -- no branch protection, no
runner -- while the tree asserted both. This corrects the documents that carried, and in
several cases CAUSED, that belief.

CLAUDE.md gains section 2b: never infer platform state from this repository. It carries
the specific API and kubectl checks for protection, runners, CI status, workloads and
Flux revisions, and the rule that a green tick is not proof anything ran (a skipped Gitea
job reports success). This is the rule whose absence produced every other finding.

.gitea/workflows/README.md and merge-gate.yaml both said "there is no remote git host,
this file is dormant". Gitea had been live for weeks. Both were written as plans and never
revisited once the plan completed. The Transition section is now marked COMPLETE and says
what is genuinely still outstanding (CLUSTER_AVAILABLE unset, so L2/L3 never runs in CI).

DECISIONS-LOG 2026-08-31 is annotated IN PLACE. Anyone reading chronologically previously
hit "required status check; runner incluster-dind online" with nothing marking it false
until a month later. The correction now sits on the bullet itself.

ci/README.md, clusters/README.md and both conformance READMEs carry a status banner: they
speak as though no cluster exists, which makes a live L2/L3 coverage gap read as an
expected phase. That framing is why the gap went unexamined.

apps/wave-1/gitea-actions-runner-secret.sops.yaml: fixed a wrong path, replaced advice to
`sops -d` into a terminal (which CLAUDE.md forbids) with the rotation script, and recorded
that a fresh token alone does not re-register a runner holding a stale /data/.runner.

apps/wave-0/plex-claim-secret.sops.yaml: the header claimed the file ships the placeholder.
It has not since the claim -- it holds the spent token, which is inert and deliberately
left in place.

catalog/plex.yaml and the plex secret both asserted a "~4-minute TTL" as fact. It was
uncited, upstream documents no expiry, and it was the basis for a since-disproven claim
that the pipeline was too slow to fit inside it. Measured: ~2m45s.

Both .sops.yaml files were verified to still decrypt after the comment edits
(`sops -d > /dev/null`), and render==golden confirms the catalog comment does not
propagate into the rendered manifest.

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

apps/wave-0/plex-claim-secret.sops.yaml

@@ -7,12 +7,20 @@
 # substitution). A braced token quoted from the upstream shell script would be a live hazard here,
 # not prose, so the upstream conditions below are described in words.
 #
-# THE VALUE SHIPPED WITH THIS FILE IS A PLACEHOLDER, DELIBERATELY — the literal string
-# `replace-me-with-a-fresh-plex-tv-claim-token`, not a credential. A https://plex.tv/claim token has
-# a ~4-minute TTL, far shorter than commit -> push -> Flux reconcile -> pod-roll, so no token
-# committed here is ever still valid when the pod starts. This file exists to make the Secret — and
-# therefore the env reference — ALWAYS RESOLVABLE IN THE FLUX GRAPH, not to carry a working token.
-# The real token is injected by the operator inside that 4-minute window: runbooks/plex-claim.md.
+# THIS FILE NO LONGER HOLDS THE PLACEHOLDER. Corrected 2026-09-29: the server was CLAIMED on that
+# date, and the value here is the SPENT token from that claim. It is inert and safe to leave --
+# upstream gates the exchange on PlexOnlineToken being ABSENT from /config, and it is now present on
+# the plex-config PVC, so this value is a NO-OP on every start whatever it holds. Deleting the Secret
+# would NOT be safe (see below), which is why a spent token stays here rather than being blanked.
+#
+# The claim token is SHORT-LIVED -- minutes. Read the countdown that plex.tv/claim renders when it
+# issues one; do NOT budget against a number written in this tree. Earlier revisions of this comment
+# asserted a "~4-minute TTL" as established fact with no citation, and upstream plexinc/pms-docker
+# documents no expiry at all. That uncited number was load-bearing for the whole procedure design.
+#
+# This file exists to make the Secret — and therefore the env reference — ALWAYS RESOLVABLE IN THE
+# FLUX GRAPH, not to carry a working token. Re-claiming (only needed after a /config wipe) is
+# scripted: infra/plex/claim-ship.sh, measured at ~2m45s end to end.
 #
 # WHY SHIPPING A PLACEHOLDER IS SAFE (verified against plexinc/pms-docker branch `master`, the
 # s6-overlay v2 script root/etc/cont-init.d/40-plex-first-run, cross-checked byte-identical against

apps/wave-1/gitea-actions-runner-secret.sops.yaml

@@ -4,7 +4,13 @@
 # against Gitea. Flux decrypts it via the sops-age key at reconcile (apps Kustomization
 # decryption is wired in clusters/dev/kustomization.yaml). Rotate by resetting the token
 # in Gitea (admin -> actions -> runners) and re-encrypting a fresh value here.
-# Recover/inspect: infra/devcontainer/dev.sh run sops -d apps/gitea-actions-runner-secret.sops.yaml
+# ROTATE: ./infra/gitea/runner-token-rotate.sh -- it mints a fresh instance-level token from the
+# Gitea API and writes it here via `sops set`, without the value ever being printed.
+# Do NOT `sops -d` this file into a terminal, a log, or an agent transcript. To check only that
+# it still decrypts, redirect: `sops -d <file> > /dev/null`.
+# NOTE: a fresh token alone may not re-register the runner. act_runner registers ONCE and keeps
+# its identity in /data/.runner on the act-runner-data PVC; if Gitea no longer holds a matching
+# row it skips registration silently. Clearing that PVC is what forces a real re-registration.
 apiVersion: v1
 kind: Secret
 metadata: