Write the EdgeZero PR 275 cutover spec #1513

Description

Write and review the design for cutting Trusted Server over to EdgeZero PR 275, and record the requirements Trusted Server handed to EdgeZero for that PR. The design covers every outbound call site, Fastly on EdgeZero's canonical lifecycle, redirects through EdgeZero, configuration, consent and privacy, failure handling, rollout and qualification, tests, and the commit sequence #1507 follows.

Done when

• The requirements doc and the cutover design are merged under docs/superpowers/specs/.
• The design ends in a review log of two or more agent review rounds, the last with nothing blocking.
• Maintainers have answered the design's open questions (merge gate, timeouts, hosted qualification, HTTP/3, in-flight pull requests, loopback bidder endpoints), and the design records the answers.

Affected area

Documentation

Related

• Pull request: Cut Trusted Server over to EdgeZero PR 275 #1506
• Epic: Integrate Auctioneer into Trusted Server on EdgeZero PR 275 #1505
• Implementation: Cut Trusted Server over to EdgeZero PR 275 #1507
• Qualification: Run Trusted Server's share of the EdgeZero PR 275 qualification #1508
• EdgeZero: feat: implement portable outbound HTTP and request lifecycle contracts edgezero#275