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]>

.gitea/workflows/README.md

@@ -40,9 +40,15 @@ and ADR-0011: **CI holds no broad kubeconfig.** L2/L3 run as an in-cluster **Cha
 *collects* its artifacts, using a narrow trigger credential referenced **by secret name only**
 (`secrets.CONFORMANCE_TRIGGER_KUBECONFIG`) — never a plaintext secret, never a cluster-admin kubeconfig.
 
-## Honest SKIP — never fake green (Phase 0)
+## Honest SKIP — never fake green
 
-**No cluster exists in Phase 0.** The gate is deliberately built so unavailable checks **SKIP loudly,
+**NOTE (2026-09-29):** this section is written in the past's voice — "Phase 0", "no cluster
+exists". **A cluster has existed for weeks** and Flux has been reconciling against it. The
+skip logic below is still correct and still honest, but read it as describing a **live
+coverage gap** (L2/L3 is not wired into CI) rather than an expected phase. Its being
+phrased as a phase is part of why the gap went unexamined.
+
+Originally: The gate is deliberately built so unavailable checks **SKIP loudly,
 they do not pass**:
 
 - The `conformance` job is `if: ${{ vars.CLUSTER_AVAILABLE == 'true' }}` — with no cluster it is
@@ -77,21 +83,29 @@ Both dirs are git-ignored (see [`.gitignore`](../../.gitignore)).
 ## Triggers & branch model (CONTRIBUTING.md)
 
 - `pull_request` → `main`: **PRs are the enforced merge gate into `main`.**
-- `push` → `feature/**`, `fix/**`, `docs/**`, `chore/**`: fast feedback on the branch. **No work on `main`.**
+- `push` → `main` only. The per-branch prefix list was removed: `act_runner` runs at capacity 1,
+  so a branch push fires a redundant run that serialises *ahead* of the PR run for the same tree.
+  **No work on `main`** — and since 2026-09-29 that is enforced, not conventional: `main` is a
+  protected branch and a direct push is rejected by the pre-receive hook (verified, not assumed).
 
-## Transition: generic-CI-now → Gitea-Actions-after-Gitea-is-up
+## Transition: COMPLETE (2026-09-29)
 
-Per [`CONTRIBUTING.md`](../../../home-network-k3s/CONTRIBUTING.md) and
-[`docs/05` §"local bootstrap → self-hosted Gitea"](../../../home-network-k3s/docs/05-gitops-and-delivery.md):
+This section used to describe a migration as pending. It has happened. Gitea is live at
+`gitea.home.keithjackson.dev`, the runner `incluster-dind` is registered and online, and
+`gate.yml` runs on every PR.
 
-1. **Now (interim):** there is **no remote git host** on this network. This workflow file is dormant —
-   but the **identical gate runs locally today** via `make -C ci gate` (R-TEST-02). Development is
-   local feature-branch → `main`, the gate enforced by convention + the local runner.
-2. **Gitea comes online early** (one of the first services onboarded) at `gitea.home.keithjackson.dev`.
-3. **CI moves to Gitea Actions:** this workflow activates unchanged. The only operational steps are
-   enabling a Gitea Actions runner and setting `vars.CLUSTER_AVAILABLE=true` +
-   `secrets.CONFORMANCE_TRIGGER_KUBECONFIG` once a dev/test cluster exists. PRs then become the
-   **platform-enforced** merge gate — the same no-work-in-main rule, now enforced by machine.
+**What took a month to notice:** the migration was recorded as done on 2026-08-31 without
+anyone checking the platform. In reality `main` had **no branch protection** and **zero
+runners were registered** until 2026-09-29. Every "the gate enforces this" statement in
+between rested on an assertion nobody verified. PR #1 — the first pull request this
+repository ever had — sat `pending` for 30.6 minutes because nothing existed to run it.
+
+So: **do not read this file, or the DECISIONS-LOG, as evidence about the live platform.**
+Query the API. `infra/gitea/` holds the scripts and the measured state.
+
+Still genuinely outstanding: `vars.CLUSTER_AVAILABLE` and
+`secrets.CONFORMANCE_TRIGGER_KUBECONFIG` are unset, so L2/L3 conformance does not run in
+CI. That is a real coverage gap, not a phase.
 
 ## Configuration (set in Gitea; referenced by name only)
 

.gitea/workflows/merge-gate.yaml

@@ -11,11 +11,14 @@
 #                                          v
 #                                     merge-gate decision  [R-TEST-03: touched subset green]
 #
-# Transition (CONTRIBUTING.md / docs/05 §"local bootstrap -> self-hosted Gitea"):
-# Today there is no Gitea host, so this file is dormant. The SAME gate is runnable
-# now via `make -C ci gate` (R-TEST-02). Once Gitea is self-hosted and Gitea
-# Actions is enabled, this workflow becomes the ENFORCED PR merge gate into main —
-# no code change required, only turning on the runner and setting CLUSTER_AVAILABLE.
+# STATUS (corrected 2026-09-29): Gitea IS hosted and Gitea Actions IS enabled; the runner
+# `incluster-dind` is online and gate.yml is the live PR gate. The text that used to sit here
+# ("Today there is no Gitea host, so this file is dormant") was stale by weeks -- it was written
+# as a plan and never revisited once the plan completed.
+#
+# THIS file is still dormant, but for the reason in the DORMANT block below -- its spec checkout
+# and L2/L3 seams are unwired -- NOT because there is no host. Do not read a stale plan as a
+# statement about the live platform; query the API instead (see infra/gitea/).
 #
 # CI holds NO broad kubeconfig. L2/L3 run as an in-cluster Chainsaw Job whose own
 # scoped ServiceAccount holds cluster access (docs/14, R-SEC-02); CI uses only a