deploy(fc-updater): bump image to v20260508-pub3-deepening-2bdf108

Promotes the fleet to FlowerCore.Updater main @ 2bdf108 which combines:
- PR #6 publish pre-signed releases (1a188f4)
- PR #7 deeper public-host privacy enforcement (8cd8544)
- PublishPreSignedAsync(stream, sig) Integration coverage (2bdf108)

Live image already imported to rke2-server and rolled via deploy-web.ps1.
This commit aligns the bluejay-infra source of truth so ArgoCD doesn't
snap the spec back to the previous tag (per
feedback_argocd_managed_image_overrides_do_not_stick).

apps/fc-updater/fc-updater.yaml

@@ -58,7 +58,7 @@ spec:
       nodeName: rke2-server
       containers:
         - name: web
-          image: localhost/fc-updater-web:v20260507-public-privacy
+          image: localhost/fc-updater-web:v20260508-pub3-deepening-2bdf108
           imagePullPolicy: Never
           ports:
             - containerPort: 8080