decommission(F4): retirar polymarket-bot — Application y manifests

Fase final de la decomisión: namespace y Application borrados del cluster,
manifests fuera de git. Dump definitivo verificado y offsite en
/data/backups/backups/polymarket-decommission/ (espejo en mega:k3s-backups/).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

argocd/application-polymarket-bot.yaml

@@ -1,18 +0,0 @@
-apiVersion: argoproj.io/v1alpha1
-kind: Application
-metadata:
-  name: polymarket-bot
-  namespace: argocd
-spec:
-  destination:
-    namespace: polymarket-bot
-    server: https://kubernetes.default.svc
-  project: default
-  source:
-    path: polymarket-bot
-    repoURL: https://git.chemavx.xyz/chemavx/k8s-manifests
-    targetRevision: main
-  syncPolicy:
-    automated:
-      prune: true
-      selfHeal: true