PERF(repo): add PriorityClasses for workloads

- Create high-priority (1000) for critical infra
- Create medium-priority (500) for observability
- Create low-priority (100) as global default

priority-classes/argocd.yaml

@@ -0,0 +1,17 @@
+apiVersion: argoproj.io/v1alpha1
+kind: Application
+metadata:
+  name: priority-classes
+  namespace: argocd
+spec:
+  project: default
+  source:
+    repoURL: https://github.com/Mayne0213/platform.git
+    targetRevision: HEAD
+    path: priority-classes/manifests
+  destination:
+    server: https://kubernetes.default.svc
+  syncPolicy:
+    automated:
+      prune: true
+      selfHeal: true

priority-classes/manifests/kustomization.yaml

@@ -0,0 +1,5 @@
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+
+resources:
+  - priority-classes.yaml

priority-classes/manifests/priority-classes.yaml

@@ -0,0 +1,28 @@
+# High Priority (1000) - Critical infrastructure
+# ArgoCD, Gitea, CNPG, Vault, MinIO
+apiVersion: scheduling.k8s.io/v1
+kind: PriorityClass
+metadata:
+  name: high-priority
+value: 1000
+globalDefault: false
+description: "High priority for critical infrastructure"
+---
+# Medium Priority (500) - Observability stack
+# Thanos, Prometheus, Loki, Tempo
+apiVersion: scheduling.k8s.io/v1
+kind: PriorityClass
+metadata:
+  name: medium-priority
+value: 500
+globalDefault: false
+description: "Medium priority for observability stack"
+---
+# Low Priority (100) - Everything else
+apiVersion: scheduling.k8s.io/v1
+kind: PriorityClass
+metadata:
+  name: low-priority
+value: 100
+globalDefault: true
+description: "Low priority for all other applications"