Wire the composition root: flags, providers, runnables, manifests, samples, docs

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

config/manager/providers_config.yaml

@@ -0,0 +1,17 @@
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: providers-config
+  namespace: system
+  labels:
+    app.kubernetes.io/name: egress-proxies-operator
+    app.kubernetes.io/managed-by: kustomize
+data:
+  # Mounted at /etc/proxy-operator/providers.yaml (--providers-config).
+  # The default ships only the kubernetes-pod provider so the operator runs
+  # out of the box; add gcp entries (type: gcp, gcp.project: ...) for real
+  # egress fleets — see config/samples/providers-config.yaml.
+  providers.yaml: |
+    providers:
+      - name: kubernetes
+        type: kubernetes