Deploy bind-operator (operator + CRDs)

Deploys the bind-operator control plane on its own so it can be verified
before any DNS clusters are created. The three BIND tiers follow as
separate PRs.

- add apps/base/bind-system: operator Deployment (image v0.1.1), RBAC,
  namespace, and CRDs pulled from the operator repo by raw URL
- add au-syd1 bind-system overlay
- register all four bind apps in the platform ApplicationSet (the DNS
  overlays are instantiated only once their dirs land in later PRs)
- add binddns-* namespaces to the platform AppProject destinations
- add schemas/bind.unkin.net/*.json so kubeconform validates the CRs

apps/base/bind-system/deployment.yaml

@@ -0,0 +1,57 @@
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: bind-operator
+  namespace: bind-system
+  labels:
+    app.kubernetes.io/name: bind-operator
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app.kubernetes.io/name: bind-operator
+  template:
+    metadata:
+      labels:
+        app.kubernetes.io/name: bind-operator
+    spec:
+      serviceAccountName: bind-operator
+      securityContext:
+        runAsNonRoot: true
+      containers:
+        - name: operator
+          image: git.unkin.net/unkin/bind-operator:v0.1.1
+          args:
+            - --metrics-bind-address=:8080
+            - --health-probe-bind-address=:8081
+            - --leader-elect
+          ports:
+            - containerPort: 8080
+              name: metrics
+            - containerPort: 8081
+              name: health
+          readinessProbe:
+            httpGet:
+              path: /readyz
+              port: 8081
+            initialDelaySeconds: 5
+            periodSeconds: 10
+          livenessProbe:
+            httpGet:
+              path: /healthz
+              port: 8081
+            initialDelaySeconds: 15
+            periodSeconds: 20
+          securityContext:
+            allowPrivilegeEscalation: false
+            readOnlyRootFilesystem: true
+            capabilities:
+              drop: ["ALL"]
+          resources:
+            requests:
+              cpu: 50m
+              memory: 64Mi
+            limits:
+              cpu: 500m
+              memory: 256Mi