chore: canonicalize legacy doc URLs across codebase [AI-7362]

Tracking issue for PR #1004.

Legacy documentation hostnames (docs.altimate.sh, docs.myaltimate.com, datamates-docs.myaltimate.com, altimate.sh marketing pages) have been consolidated. This issue tracks the mechanical URL update in source code to stop relying on 301 redirects.

Part of AI-7362 (URL canonicalization across all Altimate repos).