fc-signalcontrol: add PVC + volumeMount for SQLite data dir

Live cluster had a Longhorn PVC `signalcontrol-data` mounted at /app/data
since 2026-04-14, but the bluejay-infra git manifest never declared it. As a
result, when ArgoCD recreated the Deployment from git (after deletion to fix
an unrelated selector-label mismatch caught during cert-manager recovery),
the new pod started without /app/data and crashed with `SQLite Error 14:
unable to open database file 'data/signalcontrol.db'`.

Bring git in line with reality: declare the PVC, mount it, and switch the
Deployment to `strategy.type: Recreate` (RWO PVC blocks rolling updates per
existing memory feedback_k8s_rwo_rollout.md).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/fc-signalcontrol/fc-signalcontrol.yaml

@@ -7,6 +7,21 @@ metadata:
   labels:
     app.kubernetes.io/part-of: bluejay-infra
 ---
+apiVersion: v1
+kind: PersistentVolumeClaim
+metadata:
+  name: signalcontrol-data
+  namespace: fc-signalcontrol
+  labels:
+    app: signalcontrol-web
+spec:
+  accessModes:
+    - ReadWriteOnce
+  storageClassName: longhorn
+  resources:
+    requests:
+      storage: 1Gi
+---
 apiVersion: apps/v1
 kind: Deployment
 metadata:
@@ -16,6 +31,8 @@ metadata:
     app: signalcontrol-web
 spec:
   replicas: 1
+  strategy:
+    type: Recreate
   selector:
     matchLabels:
       app: signalcontrol-web
@@ -36,6 +53,9 @@ spec:
               value: Production
             - name: ASPNETCORE_URLS
               value: "http://+:8080"
+          volumeMounts:
+            - name: data
+              mountPath: /app/data
           resources:
             requests:
               memory: "128Mi"
@@ -55,6 +75,10 @@ spec:
               port: 8080
             initialDelaySeconds: 5
             periodSeconds: 10
+      volumes:
+        - name: data
+          persistentVolumeClaim:
+            claimName: signalcontrol-data
 ---
 apiVersion: v1
 kind: Service