feat(fc-network): add FlowerCore.Network app (read-only pfSense plane, ADR-189)

Stand up the pfSense automation plane (Phase 0, read-only) on RKE2 as an
ArgoCD-managed workload at network.iamworkin.lan.

- namespace fc-network
- Deployment fc-network-web: localhost/fc-network-web:v20260612-0b5b049,
  imagePullPolicy Never, port 5340, /healthz probes, runAsNonRoot 1654 +
  readOnlyRootFilesystem, RWO-safe RollingUpdate (maxSurge 0/maxUnavailable 1),
  auth gate-OFF, SQLite + snapshot-store + intended-model paths under /data.
- PVC fc-network-web-data (longhorn, 2Gi): SQLite index + on-box snapshot store
  (full-fidelity raw config.xml stays on-box; service surfaces redacted only).
- Service (ClusterIP 80 -> 5340), Certificate (ClusterIssuer step-ca-acme),
  IngressRoute (network.iamworkin.lan, all methods — POST ingest is local-only).
- kustomization.yaml for local previews / single-app validation.

The ApplicationSet git generator picks this up as infra-fc-network; if it lags,
the Application is applied manually (documented pattern).

apps/fc-network/certificate-web.yaml

@@ -0,0 +1,33 @@
+# Certificate for network.iamworkin.lan.
+#
+# Preflight gate: network.iamworkin.lan must resolve to 10.0.56.200 before this
+# Certificate is synced. step-ca ACME cannot see the CoreDNS wildcard
+# (*.iamworkin.lan -> 10.0.56.200) — it does an HTTP-01 challenge against the
+# resolved host. The CoreDNS wildcard template covers network.iamworkin.lan, so
+# resolution exists fleet-wide; do NOT add a pfSense DNS override (this plane is
+# read-only and holds no pfSense creds). If ACME backs off, confirm the wildcard
+# resolves first (feedback_pfsense_dns_required_for_acme).
+apiVersion: cert-manager.io/v1
+kind: Certificate
+metadata:
+  name: fc-network-web-tls
+  namespace: fc-network
+  labels:
+    app: fc-network-web
+    app.kubernetes.io/name: fc-network-web
+    app.kubernetes.io/component: web
+    app.kubernetes.io/part-of: flowercore
+    app.kubernetes.io/managed-by: argocd
+    flowercore.io/tenant-id: system
+    flowercore.io/created-by: bluejay-infra
+  annotations:
+    flowercore.io/dns-preflight: "network.iamworkin.lan must resolve to 10.0.56.200 (CoreDNS wildcard) before ACME sync"
+spec:
+  secretName: fc-network-web-tls
+  issuerRef:
+    name: step-ca-acme
+    kind: ClusterIssuer
+  dnsNames:
+    - network.iamworkin.lan
+  duration: 720h
+  renewBefore: 240h