goldmane-trail: polish follow-ups #57/#59/#61/#62/#63 + digest→#alerts

Completes the Goldmane who-talks-to-whom trail (ADR-0014), implemented by a
subagent workflow (distinct stacks in parallel, docs last):

- #57 Whisker gated ingress: ingress_factory (whisker.viktorbarzin.me,
  auth=required, Authentik-gated) + a NetworkPolicy allowing traefik->whisker:8081
  (the operator's whisker NP default-denies ingress). calico stack.
- #61 pipeline health: AggregatorDown + DigestFailing Prometheus alerts
  (prometheus_chart_values.tpl) + cluster-health check #48.
- #59 service-identity labels on the multi-Service namespaces (monitoring's 5
  TF-managed deployments + dbaas), with the KYVERNO_LIFECYCLE_V1 marker so they
  update in-place.
- #62/#63 docs: docs/runbooks/goldmane-flow-trail.md (new), service-catalog,
  security.md + monitoring.md east-west sections, ADR-0014 as-built, CONTEXT.md.
  #62 = the SQL to derive the Wave-1 per-namespace egress allowlist from the
  edge table (feeds code-8ywc; enforce-flips out of scope).

Also fixes the digest's Slack target: #security override 404s channel_not_found
because the shared alertmanager_slack_api_url webhook's app isn't a member of
#security (this likely also breaks alertmanager's slack-security receiver — flagged
in the runbook). Routed to #alerts (the webhook's working channel) until the app
is invited; verified a real digest run posts cleanly (360 edges).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docs/adr/0014-service-identity-and-east-west-observability.md

@@ -27,3 +27,9 @@ As the Service count grows we want an audit-grade record of which Service talks
 - **Enforcement gains a better data source.** Goldmane's allow/deny + policy-trace flows build the Wave 1 empirical egress allowlist faster than the current iptables-`LOG`→journald→Loki path, and policies select on namespace/label with no SA dependency.
 - **New ubiquitous language** recorded in `CONTEXT.md`: **Service identity** and **Goldmane / Whisker**.
 - **Revisit triggers:** adopt dedicated per-Service SAs if identity-aware NetworkPolicy needs a principal finer than namespace/label, or if mTLS is ever required; reconsider Retina if DNS/drop-level flow detail becomes necessary.
+
+## As-built (2026-06-25)
+
+Implemented across infra issues #57–#63. **One material deviation from the decision above:** the durable trail is NOT a Goldmane→Loki emitter (no such emitter exists in OSS Calico 3.30) — it is the **`goldmane-edge-aggregator`** service, which streams Goldmane's gRPC `Flows.Stream` API over mTLS and upserts the unique namespace-pair **edge set** (`edge(src_ns,dst_ns,action,first_seen,last_seen,flow_count)`, self-edges + empty-namespace flows dropped) into **CNPG DB `goldmane_edges`**, plus a daily `goldmane-edges-digest` CronJob → `#alerts` (the shared webhook can't reach `#security` — see runbook). The mTLS client cert **reuses the operator's Tigera-CA-signed `whisker-backend-key-pair`** rather than copying the CA private key into TF state (Goldmane verifies CA-chain only, not identity) — re-apply `stacks/goldmane-edge-aggregator` if the operator rotates it. `service-identity` labels are live on the multi-Service namespaces (`monitoring`, `dbaas`). Whisker UI is Authentik-gated at `whisker.viktorbarzin.me`. Health: Prometheus alerts `AggregatorDown` + `DigestFailing` and cluster-health check #48.
+
+Full as-built, query recipes (incl. the Wave-1 egress-allowlist derivation), and troubleshooting: [`docs/runbooks/goldmane-flow-trail.md`](../runbooks/goldmane-flow-trail.md). Stacks: `stacks/calico` (Goldmane/Whisker + Whisker ingress), `stacks/goldmane-edge-aggregator` (the trail). Code: `~/code/goldmane-edge-aggregator`.