Silence render-disposed spam, unbreak bundled skills, drop board wake

Three independently ugly bugs that all fed the same log flood:

* Electron's `WebFrameMain.send` writes every "Render frame was disposed"
  to stderr via `console.error`. When the worker fans a second
  agent-event past a reloading renderer, we produced thousands of
  identical lines and stalled the main loop on stderr I/O. Added a
  `mainFrame.detached` guard so the send is short-circuited before
  Electron's own catch block fires, and installed a targeted filter in
  `suppress-warnings.ts` (now actually imported from the entry point)
  so the specific `console.error("Error sending from webFrameMain:"…)`
  noise never reaches the terminal. Any other payload still surfaces.

* `dispatchAgentMessage` accepted the human-reader sentinel as a wake
  target when an agent replied to `__board__` — `wakeAgentIfPossible`
  then called `db.getAgent("__board__")`, threw, and the dispatcher
  kept repeating on every send. Strip `HUMAN_SENDER_ID` at
  `resolveMessageWakeTargets`, and keep a defense-in-depth guard in the
  heartbeat so a stray caller (future automation fan-out) cannot
  reintroduce the crash.

* Pi's skills loader rejects any SKILL.md whose frontmatter `name`
  diverges from its parent directory. The four bundled `my-writing-style`
  copies declared `name: writing-style-skill`, so every install emitted
  a warning and dropped the skill. They also lived as orphan gitlinks
  (mode 160000 without .gitmodules), and the global `*.md` gitignore
  hid every other SKILL.md from version control. Fixed the frontmatter
  to match the dir, converted the dangling submodules to plain trees,
  and allowlisted `builtin-skills/**/*.md` so a fresh clone carries the
  catalogue instead of silently losing it.

builtin-skills/software-engineer/devops-engineer/references/kubernetes.md

@@ -0,0 +1,154 @@
+# Kubernetes Manifests
+
+## Complete Deployment Stack
+
+```yaml
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: app
+  labels:
+    app: app
+spec:
+  replicas: 3
+  selector:
+    matchLabels:
+      app: app
+  template:
+    metadata:
+      labels:
+        app: app
+    spec:
+      containers:
+        - name: app
+          image: ghcr.io/org/app:latest
+          ports:
+            - containerPort: 3000
+          resources:
+            requests:
+              memory: "128Mi"
+              cpu: "100m"
+            limits:
+              memory: "256Mi"
+              cpu: "500m"
+          livenessProbe:
+            httpGet:
+              path: /health
+              port: 3000
+            initialDelaySeconds: 10
+            periodSeconds: 10
+          readinessProbe:
+            httpGet:
+              path: /ready
+              port: 3000
+            initialDelaySeconds: 5
+            periodSeconds: 5
+          env:
+            - name: DATABASE_URL
+              valueFrom:
+                secretKeyRef:
+                  name: app-secrets
+                  key: database-url
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: app
+spec:
+  selector:
+    app: app
+  ports:
+    - port: 80
+      targetPort: 3000
+  type: ClusterIP
+---
+apiVersion: networking.k8s.io/v1
+kind: Ingress
+metadata:
+  name: app
+  annotations:
+    cert-manager.io/cluster-issuer: letsencrypt-prod
+spec:
+  ingressClassName: nginx
+  tls:
+    - hosts: [app.example.com]
+      secretName: app-tls
+  rules:
+    - host: app.example.com
+      http:
+        paths:
+          - path: /
+            pathType: Prefix
+            backend:
+              service:
+                name: app
+                port:
+                  number: 80
+```
+
+## ConfigMap and Secrets
+
+```yaml
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: app-config
+data:
+  LOG_LEVEL: "info"
+  API_TIMEOUT: "30s"
+---
+apiVersion: v1
+kind: Secret
+metadata:
+  name: app-secrets
+type: Opaque
+stringData:
+  database-url: "postgres://user:pass@host:5432/db"
+```
+
+## Horizontal Pod Autoscaler
+
+```yaml
+apiVersion: autoscaling/v2
+kind: HorizontalPodAutoscaler
+metadata:
+  name: app-hpa
+spec:
+  scaleTargetRef:
+    apiVersion: apps/v1
+    kind: Deployment
+    name: app
+  minReplicas: 2
+  maxReplicas: 10
+  metrics:
+    - type: Resource
+      resource:
+        name: cpu
+        target:
+          type: Utilization
+          averageUtilization: 70
+```
+
+## Quick Reference
+
+| Resource | Purpose |
+|----------|---------|
+| Deployment | Manages ReplicaSets, rolling updates |
+| Service | Internal load balancing, DNS |
+| Ingress | External HTTP/HTTPS routing |
+| ConfigMap | Non-sensitive configuration |
+| Secret | Sensitive data (base64 encoded) |
+| HPA | Auto-scaling based on metrics |
+| PVC | Persistent storage claims |
+
+## Common kubectl Commands
+
+```bash
+kubectl apply -f deployment.yaml
+kubectl get pods -l app=app
+kubectl describe pod <pod-name>
+kubectl logs -f <pod-name>
+kubectl exec -it <pod-name> -- /bin/sh
+kubectl rollout status deployment/app
+kubectl rollout undo deployment/app
+```