Provisions production-grade AWS Transit Gateway topologies with secure defaults: TGW creation (Amazon ASN, DNS support, multicast), VPC attachments with subnet selections, TGW route tables (association + propagation), inter-region peering connections, Connect attachments (GRE tunnels for SD-WAN), TGW Network Manager (global network visualization), cross-account sharing via RAM, and AWS Cloud WAN integration. Emits READY_TO_DEPLOY with an ordered CLI plan or PREREQUISITES_MISSING with the specific gap. Use when building hub-and-spoke or mesh topologies, configuring inter-region TGW peering, deploying Connect attachments for SD-WAN appliances, sharing a TGW across accounts …
