monitoring: consolidate all Slack alerting to #alerts, abandon #security

The dedicated #security Slack channel was unreachable: the shared incoming
webhook (Vault secret/viktor -> alertmanager_slack_api_url) belongs to a
Slack app that isn't a member of #security, so any channel override on it
returns HTTP 404 channel_not_found. The goldmane-edges-digest was silently
failing for that reason.

Per request ("dump the security channel, post in an existing one"), route
everything to #alerts instead:
- alertmanager slack-security receiver -> #alerts (keeps its [SECURITY/<sev>]
  title styling so security-lane alerts still stand out in the shared channel)
- goldmane-edges-digest CronJob SLACK_CHANNEL -> #alerts (comment only; value
  was already switched and applied last change)
- AggregatorDown / DigestFailing alert summaries reworded to say #alerts
- docs swept (security.md, monitoring.md, ADR-0014, goldmane runbook,
  .claude/CLAUDE.md, service-catalog, CONTEXT.md) to drop the
  "invite the app / flip back to #security" caveats and state the
  #security abandonment + #alerts consolidation as the current routing.

Monitoring stack applied (alertmanager rolled, live config verified:
slack-security channel is now #alerts).

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

.claude/CLAUDE.md

@@ -233,7 +233,7 @@ the workflow's built-in `GITHUB_TOKEN` (`packages: write`).
 - **External monitoring**: `[External] <service>` monitors in Uptime Kuma test full external path (DNS → Cloudflare → Tunnel → Traefik). Divergence metric `external_internal_divergence_count` → alert `ExternalAccessDivergence` (15min). Config: `stacks/uptime-kuma/`, targets from `cloudflare_proxied_names` in `config.tfvars` (17 remaining centrally-managed hostnames; most DNS records now auto-created by `ingress_factory` `dns_type` param).
 - Key alerts: OOMKill, pod replica mismatch, 4xx/5xx error rates, UPS battery, CPU temp, SSD writes, NFS responsiveness, ClusterMemoryRequestsHigh (>85%), ContainerNearOOM (>85% limit), PodUnschedulable, ExternalAccessDivergence, ImmichSmartSearchSlow (context-search latency / clip_index cache eviction).
 - **E2E email monitoring**: CronJob `email-roundtrip-monitor` (every 20 min) sends test email via Brevo HTTP API to `smoke-test@viktorbarzin.me` (catch-all → `spam@`), verifies IMAP delivery, deletes test email, pushes metrics to Pushgateway + Uptime Kuma. Alerts: `EmailRoundtripFailing` (60m), `EmailRoundtripStale` (60m), `EmailRoundtripNeverRun` (60m). Outbound relay: Brevo EU (`smtp-relay.brevo.com:587`, 300/day free — migrated from Mailgun). Inbound external traffic enters via pfSense HAProxy on `10.0.20.1:{25,465,587,993}`, which forwards to k8s `mailserver-proxy` NodePort (30125-30128) with `send-proxy-v2`. Mailserver pod runs alt PROXY-speaking listeners (2525/4465/5587/10993) alongside stock PROXY-free ones (25/465/587/993) for intra-cluster clients. Real client IPs recovered from PROXY v2 header despite kube-proxy SNAT (replaces pre-2026-04-19 MetalLB `10.0.20.202` ETP:Local scheme; see bd code-yiu + `docs/runbooks/mailserver-pfsense-haproxy.md`). Vault: `brevo_api_key` in `secret/viktor` (probe + relay).
-- **Authentik walling-off guard**: `blackbox-exporter` (monitoring ns, `stacks/monitoring/modules/monitoring/authentik_walloff_probe.tf`) probes each must-stay-public `auth = "none"` carve-out URL with `no_follow_redirects` and FAILS (`fail_if_header_matches` on `Location`) iff it 302s to Authentik. Catches a carve-out regressing (TF revert / deploy / `ingress_factory` `auth` default flipping back to `"required"`). Scrape job `blackbox-authentik-walloff` (1m) → alert `AuthentikWallingOffPublicPath` (`probe_failed_due_to_regex == 1`, for 10m, `lane=security` → `#security` Slack). **To guard a new carve-out: add one line to `local.authentik_walloff_targets`** (a `service → URL` map; `valid_status_codes` includes 301/302 so legit redirects/404s stay green — only the Authentik `Location` fails the probe). `curl -sI '<url>'` must NOT show a Location to `authentik.viktorbarzin.me` before adding.
+- **Authentik walling-off guard**: `blackbox-exporter` (monitoring ns, `stacks/monitoring/modules/monitoring/authentik_walloff_probe.tf`) probes each must-stay-public `auth = "none"` carve-out URL with `no_follow_redirects` and FAILS (`fail_if_header_matches` on `Location`) iff it 302s to Authentik. Catches a carve-out regressing (TF revert / deploy / `ingress_factory` `auth` default flipping back to `"required"`). Scrape job `blackbox-authentik-walloff` (1m) → alert `AuthentikWallingOffPublicPath` (`probe_failed_due_to_regex == 1`, for 10m, `lane=security` → posts to `#alerts` via the `slack-security` receiver, which keeps its `[SECURITY]` styling; the dedicated `#security` channel was abandoned 2026-06-25 — the shared webhook's app isn't a member of it). **To guard a new carve-out: add one line to `local.authentik_walloff_targets`** (a `service → URL` map; `valid_status_codes` includes 301/302 so legit redirects/404s stay green — only the Authentik `Location` fails the probe). `curl -sI '<url>'` must NOT show a Location to `authentik.viktorbarzin.me` before adding.
 
 ## Security Posture (Wave 1 — locked 2026-05-18)
 
@@ -241,10 +241,10 @@ Plan in `docs/architecture/security.md` + response playbook in `docs/runbooks/se
 
 - **Identity allowlist for security rules**: ONLY `me@viktorbarzin.me`. NOT `viktor@viktorbarzin.me`, NOT `emo@viktorbarzin.me` (those don't exist). emo's identity scheme is unknown — ask before assuming.
 - **Source-IP allowlist (K2, K9, V7, S1)**: `10.0.20.0/22`, `192.168.1.0/24` (Proxmox + Sofia LAN), K8s pod CIDR, K8s service CIDR, Headscale tailnet. **Policy: no public-IP access** — Vault, kube-apiserver, PVE sshd must transit LAN or Headscale. **One documented exception (2026-06-11): break-glass SSH** — PVE sshd on a WAN-exposed `:52222`, key-only, dedicated break-glass key only (`Match LocalPort`), rate-limited + fail2ban; intentionally cluster-independent so it survives an outage. As-built `docs/runbooks/breakglass-ssh.md`. (Replaced the 2026-05-30 port-knock design — circular Vault dep caused a lockout.)
-- **Response model**: (I) Slack-only daily skim. All security alerts via Loki ruler → Alertmanager → `#security` Slack receiver. Single channel with severity labels inside (critical/warning/info). No paging.
+- **Response model**: (I) Slack-only daily skim. All security alerts via Loki ruler → Alertmanager → the `slack-security` receiver, which posts to `#alerts` (it keeps its `[SECURITY/<sev>]` title styling so security-lane alerts stand out). Severity labels carried in the alert (critical/warning/info). No paging. The dedicated `#security` channel was abandoned 2026-06-25 — the shared `alertmanager_slack_api_url` webhook's Slack app isn't a member of it (a `#security` override 404s), so everything consolidated to `#alerts`.
 - **Kyverno policies (wave 1)**: `deny-privileged-containers`, `deny-host-namespaces`, `restrict-sys-admin`, `require-trusted-registries` flip Audit→Enforce with the 31-namespace exclude list (memory id=1970). `failurePolicy: Ignore` preserved. Cosign `verify-images` deferred.
 - **NetworkPolicy default-deny egress (wave 1)**: observe-then-enforce (γ approach) — Calico flow logs cluster-wide + GlobalNetworkPolicy log-only on tier 3+4, build empirical allowlist after 1 week, phased per-namespace enforce starting `recruiter-responder`. Tier 0/1/2 deferred. **The internal (ns-to-ns) half of each allowlist now derives faster from the east-west flow trail** (below): `SELECT DISTINCT dst_ns FROM edge WHERE src_ns='<ns>' AND action='allow'`. External egress is NOT in that table (empty-ns flows dropped) — those still come from the Calico flow-log W1.6 snapshot. Enforce-flips remain out of scope of the trail (observe-and-derive only; beads `code-8ywc`).
-- **East-west flow trail (who-talks-to-whom, ADR-0014)**: Calico **Goldmane** (`goldmane.calico-system:7443`, gRPC/mTLS, ~60-min in-memory ring buffer — no etcd writes) + **Whisker** live UI (`whisker.viktorbarzin.me`, Authentik-gated) → **`goldmane-edge-aggregator`** streams Goldmane's `Flows.Stream` over mTLS and upserts the namespace-pair **edge set** (`edge(src_ns,dst_ns,action,first_seen,last_seen,flow_count)`, self-edges + public-internet flows dropped) into **CNPG DB `goldmane_edges`** → daily **`goldmane-edges-digest`** CronJob posts first-seen edges to `#alerts` (the shared webhook's Slack app isn't in `#security` → 404 channel_not_found; flip `SLACK_CHANNEL` back once invited — see runbook). **CERT-REUSE GOTCHA**: the aggregator's mTLS client cert reuses the operator's Tigera-CA-signed `whisker-backend-key-pair` Secret (Goldmane verifies CA-chain only) — **re-apply `stacks/goldmane-edge-aggregator` if the operator rotates it** (symptom: no `last_seen` updates, `AggregatorDown`). Service identity = namespace, + `service-identity` label only in `monitoring`/`kube-system`/`dbaas`. Health: `AggregatorDown` + `DigestFailing` alerts + cluster-health #48. Runbook: `docs/runbooks/goldmane-flow-trail.md`. (Goldmane is OSS tech-preview — reversible operator-CR toggle in `stacks/calico/main.tf`.)
+- **East-west flow trail (who-talks-to-whom, ADR-0014)**: Calico **Goldmane** (`goldmane.calico-system:7443`, gRPC/mTLS, ~60-min in-memory ring buffer — no etcd writes) + **Whisker** live UI (`whisker.viktorbarzin.me`, Authentik-gated) → **`goldmane-edge-aggregator`** streams Goldmane's `Flows.Stream` over mTLS and upserts the namespace-pair **edge set** (`edge(src_ns,dst_ns,action,first_seen,last_seen,flow_count)`, self-edges + public-internet flows dropped) into **CNPG DB `goldmane_edges`** → daily **`goldmane-edges-digest`** CronJob posts first-seen edges to `#alerts` (consolidated to `#alerts`; the `#security` channel was abandoned 2026-06-25 — the shared webhook's Slack app isn't a member of it, so a `#security` override 404s; see runbook). **CERT-REUSE GOTCHA**: the aggregator's mTLS client cert reuses the operator's Tigera-CA-signed `whisker-backend-key-pair` Secret (Goldmane verifies CA-chain only) — **re-apply `stacks/goldmane-edge-aggregator` if the operator rotates it** (symptom: no `last_seen` updates, `AggregatorDown`). Service identity = namespace, + `service-identity` label only in `monitoring`/`kube-system`/`dbaas`. Health: `AggregatorDown` + `DigestFailing` alerts + cluster-health #48. Runbook: `docs/runbooks/goldmane-flow-trail.md`. (Goldmane is OSS tech-preview — reversible operator-CR toggle in `stacks/calico/main.tf`.)
 - **What's NOT in scope**: canary tokens (rejected — self-trigger risk with Viktor's normal `vault kv list secret/viktor` and `kubectl get secret -A` workflows), Falco/Tetragon (too noisy for Slack-only daily check), Cloudflare/GitHub audit polling (deferred to wave 2).
 
 ## Storage & Backup Architecture

.claude/reference/service-catalog.md

@@ -39,7 +39,7 @@
 ## Active Use
 | Service | Description | Stack |
 |---------|-------------|-------|
-| goldmane-edge-aggregator | Durable who-talks-to-whom audit trail (ADR-0014 / #58). Go service: `aggregate` Deployment streams Goldmane's gRPC `Flows.Stream` (mTLS) and upserts the low-cardinality namespace-pair edge set (`edge(src_ns,dst_ns,action,first_seen,last_seen,flow_count)`) into CNPG DB `goldmane_edges`; `goldmane-edges-digest` CronJob posts first-seen edges daily to `#security`. mTLS client cert REUSES the operator's `whisker-backend-key-pair` (re-apply if rotated). Tier-4-aux. Image `ghcr.io/viktorbarzin/goldmane-edge-aggregator` (private). Runbook: [goldmane-flow-trail.md](../../docs/runbooks/goldmane-flow-trail.md). | goldmane-edge-aggregator |
+| goldmane-edge-aggregator | Durable who-talks-to-whom audit trail (ADR-0014 / #58). Go service: `aggregate` Deployment streams Goldmane's gRPC `Flows.Stream` (mTLS) and upserts the low-cardinality namespace-pair edge set (`edge(src_ns,dst_ns,action,first_seen,last_seen,flow_count)`) into CNPG DB `goldmane_edges`; `goldmane-edges-digest` CronJob posts first-seen edges daily to `#alerts` (the `#security` channel was abandoned 2026-06-25 — shared webhook's app isn't a member of it). mTLS client cert REUSES the operator's `whisker-backend-key-pair` (re-apply if rotated). Tier-4-aux. Image `ghcr.io/viktorbarzin/goldmane-edge-aggregator` (private). Runbook: [goldmane-flow-trail.md](../../docs/runbooks/goldmane-flow-trail.md). | goldmane-edge-aggregator |
 | mailserver | Email (docker-mailserver) | mailserver |
 | shadowsocks | Proxy | shadowsocks |
 | webhook_handler | Webhook processing | webhook_handler |