WP-12: Kubernetes overview and workload actions

kube-rs gateway (nodes, namespaces, deployments/statefulsets/daemonsets with
images, PVCs; rollout restart, scale, set image via patches) using the
microk8s kubeconfig by default, fake gateway for dev, /api/cluster routes,
Kubernetes page with node cards, workload table with admin actions and PVC
list. Also implements the streaming command runner that WP-11 relied on.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

frontend/src/components/AppShell.vue

@@ -7,6 +7,7 @@ const router = useRouter()
 const nav = [
   { to: '/', label: 'Dashboard' },
   { to: '/updates', label: 'Updates' },
+  { to: '/cluster', label: 'Kubernetes' },
   { to: '/vulnerabilities', label: 'Vulnerabilities' },
   { to: '/backups', label: 'Backups' },
   { to: '/jobs', label: 'Jobs' },

frontend/src/components/WorkloadTable.vue

@@ -0,0 +1,61 @@
+<script setup lang="ts">
+import type { Workload } from '../api/types'
+
+defineProps<{ workloads: Workload[]; canAct: boolean }>()
+defineEmits<{ restart: [w: Workload]; scale: [w: Workload]; image: [w: Workload] }>()
+</script>
+
+<template>
+  <table class="w-full text-left text-sm">
+    <thead class="border-b border-gray-200 text-gray-500">
+      <tr>
+        <th class="py-2">Namespace</th>
+        <th>Name</th>
+        <th>Kind</th>
+        <th>Ready</th>
+        <th>Images</th>
+        <th></th>
+      </tr>
+    </thead>
+    <tbody>
+      <tr
+        v-for="w in workloads"
+        :key="`${w.namespace}/${w.kind}/${w.name}`"
+        class="border-b border-gray-100"
+        :class="w.ready < w.desired ? 'bg-red-50' : ''"
+      >
+        <td class="py-1.5">{{ w.namespace }}</td>
+        <td class="font-mono">{{ w.name }}</td>
+        <td>{{ w.kind }}</td>
+        <td :class="w.ready < w.desired ? 'font-medium text-red-700' : ''">
+          {{ w.ready }}/{{ w.desired }}
+        </td>
+        <td class="font-mono text-xs text-gray-600">
+          <div v-for="c in w.containers" :key="c.name">{{ c.image }}</div>
+        </td>
+        <td class="space-x-3 whitespace-nowrap text-right">
+          <template v-if="canAct">
+            <button
+              name="restart"
+              class="text-blue-600 hover:underline"
+              @click="$emit('restart', w)"
+            >
+              Restart
+            </button>
+            <button
+              v-if="w.kind !== 'daemonset'"
+              name="scale"
+              class="text-blue-600 hover:underline"
+              @click="$emit('scale', w)"
+            >
+              Scale
+            </button>
+            <button name="image" class="text-blue-600 hover:underline" @click="$emit('image', w)">
+              Set image
+            </button>
+          </template>
+        </td>
+      </tr>
+    </tbody>
+  </table>
+</template>