refactor(apps): move forte-drop apps from base to upc-dev overlay

forte-drop, forte-drop-mcp and forte-drop-postgresql lived under apps/base/
but were only ever wired into the upc-dev overlay (never listed in
apps/base/kustomization.yaml). They carry hackathon-domain hardcoded values
and must not sync to upc-prod, so they belong in the overlay alongside
dbunk-demo — per danijel.simeunovic's review on PR #18.

- git mv the three dirs into apps/overlays/upc-dev/ (history preserved)
- rewrite overlay kustomization refs from ../../base/forte-drop* to local
- repoint forte-drop-postgresql Application path
  apps/base/... -> apps/overlays/upc-dev/forte-drop-postgresql/resources

Render-verified: kubectl kustomize apps/overlays/upc-dev differs only by the
postgres path line; apps/overlays/upc-prod render byte-identical (forte-drop
never reaches prod).

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

apps/overlays/upc-dev/forte-drop/forte-drop.yaml

@@ -0,0 +1,37 @@
+apiVersion: argoproj.io/v1alpha1
+kind: Application
+metadata:
+  name: forte-drop
+  namespace: argocd
+  annotations:
+    argocd.argoproj.io/sync-wave: "1"
+    notifications.argoproj.io/subscribe.on-sync-succeeded.slack: ""
+    notifications.argoproj.io/subscribe.on-sync-failed.slack: ""
+    notifications.argoproj.io/subscribe.on-degraded.slack: ""
+  labels:
+    app.kubernetes.io/name: forte-drop
+    app.kubernetes.io/part-of: apps
+    app.kubernetes.io/managed-by: argocd
+  finalizers:
+  - resources-finalizer.argocd.argoproj.io
+spec:
+  project: default
+  sources:
+  - repoURL: ssh://git@git.forteapps.net:2222/Forte/forte-helm.git
+    path: forteapp
+    targetRevision: HEAD
+    helm:
+      valueFiles:
+      - $values/forte-drop/values.yaml
+  - repoURL: ssh://git@git.forteapps.net:2222/Forte/helm-prod-values.git
+    targetRevision: HEAD
+    ref: values
+  destination:
+    server: https://kubernetes.default.svc
+    namespace: forte-drop
+  syncPolicy:
+    automated:
+      prune: true
+      selfHeal: true
+    syncOptions:
+    - CreateNamespace=true