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-pdb.yaml

@@ -0,0 +1,24 @@
+# Keep at least 1 web pod up during voluntary disruptions (node drain, upgrade).
+# Pairs with replicaCount: 2 so a drain can evict one pod while the other serves.
+#
+# Selector verified against live forteapp-chart deployments (mcp10x, argocd-mcp):
+# the chart's pod selector is {app.kubernetes.io/instance, app.kubernetes.io/name,
+# component: app} where instance/name == the ArgoCD Application (Helm release) name.
+# Using all three labels also disambiguates the web pods from the forte-drop-mcp
+# deployment that shares the forte-drop namespace (its instance/name == forte-drop-mcp).
+apiVersion: policy/v1
+kind: PodDisruptionBudget
+metadata:
+  name: forte-drop-web
+  namespace: forte-drop
+  labels:
+    app.kubernetes.io/name: forte-drop
+    app.kubernetes.io/part-of: apps
+    app.kubernetes.io/managed-by: argocd
+spec:
+  minAvailable: 1
+  selector:
+    matchLabels:
+      app.kubernetes.io/instance: forte-drop
+      app.kubernetes.io/name: forte-drop
+      component: app