docs: v2.1.0 release polish — strip internal bundle/phase tags, update status for OIDC ship

README:
- Rewrite Status block: drop the stale 'federated identity not yet
  shipped' line; flag v2.1.0 OIDC + sessions + back-channel logout
  + break-glass as early-access; encourage GitHub issues for IdP
  rough edges. (A1 framing — keep early-access umbrella, no
  SAML/WebAuthn/JIT roadmap teaser.)
- Add OIDC SSO bullet to 'What it does' covering per-IdP runbooks,
  group-claim → role mapping, AES-256-GCM client_secret encryption,
  JWKS auto-refresh, PKCE-S256, RFC 9700 §4.7.1 pre-login binding,
  RFC 9207 iss check, __Host- cookies, CSRF rotation, idle+absolute
  expiry, BCL, break-glass admin.
- Update Security paragraph: three auth paths (API keys / OIDC /
  break-glass), HMAC-signed sessions, CSRF rotation, RFC OIDC BCL.
- Correct CI coverage thresholds against
  .github/coverage-thresholds.yml (service 70%, handler 75%,
  crypto 88%, auth packages 85-95%); 'static analysis' replaces
  the inflated '11 linters' claim (actual count is 4 active).

Docs B3 sweep — strip operator-facing 'Bundle N' / 'Phase N' tags:
- docs/operator/auth-threat-model.md — rewrite intro; rename 5 H2
  sections (API-key + RBAC defenses / OIDC + sessions + break-glass
  defenses / OIDC + sessions threat catalogue / Closed federated-
  identity threats / Future-work threats); clean ~12 H3/prose hits.
- docs/operator/rbac.md — strip Bundle 1 framing from intro,
  scope_id deferral note, MCP tools section, day-0 bootstrap, and
  'Where to look next'.
- docs/operator/auth-benchmarks.md — drop 'Phase 14' framing from
  title intro, hardware floor caption, result table caption,
  methodology, and pre-merge audit section.
- docs/operator/security.md — already cleaned earlier this session
  (RBAC / day-0 / approval-bypass / OIDC federation / sessions /
  OIDC first-admin / break-glass H3s).
- docs/operator/oidc-runbooks/{index,keycloak,authentik,okta,
  azure-ad}.md — strip Auth Bundle 2 framing + Phase 10/3/4
  references; replace with feature-name prose.
- docs/operator/legacy-clients-tls-1.2.md — drop Bundle F / M-023
  audit-reference framing; keep CWE-326.
- docs/operator/database-tls.md — drop Bundle B / M-018 framing
  from intro + Helm section.
- docs/operator/runbooks/disaster-recovery.md — drop 'Production
  hardening II Phase 10' status callout.
- docs/migration/oidc-enable.md — retitle 'Enable OIDC SSO';
  strip Bundle 1/2 framing from prereqs, troubleshooting, related
  docs; update __Host- cookie callout from 'audit MED-14' to
  v2.1.0-BREAKING.
- docs/migration/api-keys-to-rbac.md — strip Bundle 1 framing from
  intro, migration table, IsAdmin section, and cross-references.
- docs/migration/acme-from-cert-manager.md — strip residual
  'Phase 5' tags from cert-manager integration test references.
- docs/reference/configuration.md — retitle Auth section.
- docs/reference/profiles.md — strip Bundle 1 Phase 9 framing
  from RequiresApproval section + Related list.
- docs/reference/auth-standards-implemented.md — rewrite intro
  (API-key + RBAC + OIDC + sessions + back-channel logout +
  break-glass); rename 'Bundle 1 (RBAC) standards covered
  separately' H2; clean per-row Phase references.
- docs/README.md — rewrite nav-table entries to drop Bundle 1/2
  parentheticals; retitle 'Enable OIDC SSO' migration entry.

No code or test changes; pure operator-facing prose polish for
the v2.1.0 tag.

docs/migration/acme-from-cert-manager.md

@@ -16,7 +16,7 @@ through cert-manager 1.15+. Target audience: Kubernetes operator who
 has never deployed certctl before and wants a working
 `Certificate` → `Secret` flow on their cluster in under 30 minutes.
 
-The Phase 5 integration test (`make acme-cert-manager-test`) automates
+The cert-manager integration test (`make acme-cert-manager-test`) automates
 exactly the recipe below. The YAML snippets in this doc are byte-equal
 to the files under `deploy/test/acme-integration/` — re-running the
 test from a fresh clone produces the same results documented here.
@@ -24,7 +24,7 @@ test from a fresh clone produces the same results documented here.
 ## Prereqs
 
 - A Kubernetes cluster (kind / k3d / EKS / GKE / AKS / on-prem). For
-  local trial, `kind v0.20+` works exactly the way the Phase 5 test
+  local trial, `kind v0.20+` works exactly the way the integration test
   uses it. The kind config lives at
   [`deploy/test/acme-integration/kind-config.yaml`](../deploy/test/acme-integration/kind-config.yaml).
 - `kubectl` v1.27+, `helm` v3.13+.
@@ -37,7 +37,7 @@ test from a fresh clone produces the same results documented here.
 
   which is the same idempotent installer the integration test uses.
 - A certctl Helm chart published to a registry your cluster can pull
-  from. The Phase 5 test uses an `image.tag=test` placeholder; production
+  from. The integration test uses an `image.tag=test` placeholder; production
   deployments use the actual image tag for your release line.
 
 ## Step 1 — Deploy certctl-server
@@ -99,7 +99,7 @@ recipe lives in
 ## Step 4 — Apply the ClusterIssuer
 
 ```yaml
-# Phase 5 — sample ClusterIssuer for the certctl trust_authenticated
+# sample ClusterIssuer for the certctl trust_authenticated
 # auth mode (RFC 8555 §6 + certctl auth_mode=trust_authenticated, where
 # the JWS-authenticated ACME account is trusted to issue any identifier
 # the profile policy permits — no per-identifier ownership challenges).
@@ -169,7 +169,7 @@ HTTP-01 to work.
 ## Step 5 — Apply the Certificate
 
 ```yaml
-# Phase 5 — Certificate resource the integration test applies and
+# Certificate resource the integration test applies and
 # waits for. The certctl-test-trust ClusterIssuer (trust_authenticated
 # mode) issues the cert without any solver round-trip; the resulting
 # Secret 'test-com-tls' is asserted to carry tls.crt + tls.key.
@@ -262,4 +262,4 @@ helm uninstall certctl-test
 - [`docs/acme-traefik-walkthrough.md`](./acme-from-traefik.md) —
   Traefik-side recipe.
 - [`deploy/test/acme-integration/`](../deploy/test/acme-integration/) —
-  Phase 5 integration test (the same recipe, automated).
+  cert-manager integration test (the same recipe, automated).