W-24232213-direct-connect-kt

[kevintroller]

Summary

• Expands CloudHub Anypoint VPC Direct Connect docs with HA architecture, prerequisites, configuration steps, and automatic BGP failover (W-24232213).
• Keeps the 95 route table entry limit and documents Direct Connect Gateway as a customer-side attachment to Transit Gateway (removes “Direct Connect gateways are not supported”).
• Adds the HA topology diagram and a cross-link from the Direct Connect request procedure.

Test plan

• Confirm the Direct Connect HA section renders on Anypoint VPC Connectivity Methods, including vpc-overview-dx-ha.png.
• Confirm xrefs: Transit Gateway attach procedure, Direct Connect request procedure, AWS Direct Connect Locations, and AWS BGP routing policies.
• Confirm the request-procedure page links to #direct-connect-high-availability.
• SME review: two-location DX + DX Gateway + TGW topology, BGP active/standby vs active/active, and the 95-route limit.