feat(iac): scaffold orca-platform layout (M1.1)

Lands manifests/, overlays/, dns/, scripts/, Makefile per M1.1. Bundles yourplatform.com→breakpilot.com rename. vms/ removed (out-of-scope for Orca).

Refs: M1.1

overlays/prod/overlay.toml

@@ -0,0 +1,15 @@
+# Prod overlay.
+#
+# Selects manifests under vm-edge / vm-control / vm-data. Stage manifests
+# (manifests/stage/) are excluded from prod apply.
+
+[env]
+name = "prod"
+api_url = "${ORCA_PROD_API_URL}"
+
+[deploy]
+include_dirs = ["manifests/vm-edge", "manifests/vm-control", "manifests/vm-data"]
+
+[image]
+# Default tag for prod; release.yaml retags `env-stage` → `v$VERSION` + `env-prod`.
+default_tag = "env-prod"