feat(infra): forte-drop postgres + minio for upc-dev

Two new ArgoCD Applications:
- forte-drop-postgresql: in-cluster Postgres 16 StatefulSet, 5Gi PVC,
  POSTGRES_DB=drops, creds from forte-drop-pg-creds SealedSecret.
- forte-drop-minio: in-cluster MinIO StatefulSet, 20Gi PVC, bootstrap
  Job creates the 'drops' bucket post-sync, creds from
  forte-drop-minio-creds SealedSecret.

Both live in namespace 'forte-drop'. Mirrors the Vaultwarden pattern.

Sealed secrets are added in a follow-up commit by the maintainer:
  kubeseal --fetch-cert > pub.pem
  kubeseal --cert pub.pem --format yaml < private/forte-drop-pg-creds.yaml > \
    infra/overlays/upc-dev/forte-drop-postgresql/resources/forte-drop-pg-creds-sealed.yaml
  kubeseal --cert pub.pem --format yaml < private/forte-drop-minio-creds.yaml > \
    infra/overlays/upc-dev/forte-drop-minio/resources/forte-drop-minio-creds-sealed.yaml

infra/overlays/upc-dev/forte-drop-minio/forte-drop-minio.yaml

@@ -0,0 +1,40 @@
+apiVersion: argoproj.io/v1alpha1
+kind: Application
+metadata:
+  name: forte-drop-minio
+  namespace: argocd
+  annotations:
+    argocd.argoproj.io/sync-wave: "0"
+  labels:
+    app.kubernetes.io/name: forte-drop-minio
+    app.kubernetes.io/part-of: apps
+    app.kubernetes.io/managed-by: argocd
+  finalizers:
+  - resources-finalizer.argocd.argoproj.io
+spec:
+  project: default
+
+  source:
+    repoURL: ssh://git@git.forteapps.net:2222/Forte/launchpad.git
+    targetRevision: HEAD
+    path: infra/overlays/upc-dev/forte-drop-minio/resources
+
+  destination:
+    server: https://kubernetes.default.svc
+    namespace: forte-drop
+
+  syncPolicy:
+    automated:
+      prune: true
+      selfHeal: true
+      allowEmpty: false
+    syncOptions:
+    - CreateNamespace=true
+    - Validate=true
+    - ServerSideApply=true
+
+  ignoreDifferences:
+  - group: apps
+    kind: StatefulSet
+    jsonPointers:
+    - /spec/volumeClaimTemplates