Identity-only tsjs mode #1594

Summary

Identity-only tsjs mode.

Part of #1558, server-side identity on every adapter. Plan ID T15, planned in wave 5 (MVP: Fastly and Axum); priority P1, size M. Design: spec; order and dependencies: plan.

Requirements

WB-6 Identity-only page script

A tsjs mode captures Prebid's IDs without the auction shim, reads the mirror cookie and merges the IDs into Prebid.

Current state

What the code does today, from the design's survey at the revisions it names:

• WB-6: the ts-eids capture runs only inside the shim, and nothing reads the mirror.

Acceptance criteria

• WB-6: In that mode Prebid receives the mirrored IDs and no Trusted Server bidder is added to ad units

Dependencies

Blocked by:

• PR Mirror provider EIDs to a cookie and run pull sync as an identity provider #1489 Mirror provider EIDs to a cookie and run pull sync as an identity provider

Blocks:

• Injected script calls the EC route on consent and merges the IDs into Prebid #1599 Injected script calls the EC route on consent and merges the IDs into Prebid (new in this plan)

Related pull requests

• Mirror provider EIDs to a cookie and run pull sync as an identity provider #1489 Mirror provider EIDs to a cookie and run pull sync as an identity provider: must merge first.

  Fixes the plan asks of Mirror provider EIDs to a cookie and run pull sync as an identity provider #1489

  Cap every mirrored ID's expiry at 30 days where the mirror is built (mirror.rs:236-247), not in validation, because SID-5 keeps SharedID Never in the record. An unstated expiry still becomes Expiry::Never (coordinator/validate.rs:135-138), pull sync is its only production source (pull_sync.rs:145), and such IDs reach the cookie with no exp under a one-year Max-Age. The 30-day clamp on stated expiries comes from Add identity providers for ID5, LiveIntent, LiveRamp, ConnectID and UID2 #1488. Answer its open threads, including the one on any_due skipping cookie-read opt-outs.