Cloud and Infrastructure Update Q3 2024

https://cppalliance.org/sam/2024/10/21/SamsQ3Update.html

Boost 1.86.0 was released with Fastly CDN support; release scripts, Docker images, and AWS S3 uploads were improved. Build docs, site outage handling, local dev bootstrap, Xapian search, CI pipelines, Terraform runners, and billing/analytics were updated.