feat(platform): add priority-classes app with low/power/medium/high classes

apps/base/priority-classes/kustomization.yaml

@@ -0,0 +1,6 @@
+---
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+
+resources:
+  - priorityclasses.yaml

apps/base/priority-classes/priorityclasses.yaml

@@ -0,0 +1,36 @@
+---
+apiVersion: scheduling.k8s.io/v1
+kind: PriorityClass
+metadata:
+  name: low
+value: 100
+preemptionPolicy: Never
+globalDefault: false
+description: "Low-importance workloads. Can be evicted under pressure but will not preempt other pods."
+---
+apiVersion: scheduling.k8s.io/v1
+kind: PriorityClass
+metadata:
+  name: power
+value: 100
+preemptionPolicy: Never
+globalDefault: false
+description: "Compute-heavy workloads with low scheduling importance. Evictable under pressure."
+---
+apiVersion: scheduling.k8s.io/v1
+kind: PriorityClass
+metadata:
+  name: medium
+value: 10000
+preemptionPolicy: PreemptLowerPriority
+globalDefault: false
+description: "Standard workloads. Will preempt low-priority pods if the cluster is under pressure."
+---
+apiVersion: scheduling.k8s.io/v1
+kind: PriorityClass
+metadata:
+  name: high
+value: 100000
+preemptionPolicy: PreemptLowerPriority
+globalDefault: false
+description: "High-importance services. Will preempt medium- and low-priority pods if necessary."