chore(main): release 5.7.0

[github-actions]

🤖 I have created a release beep boop

5.7.0 (2026-05-21)

Features

• adagents: fetch_agent_authorizations_from_directory for AAO inverse lookup (#769) (1c4e57d)
• adagents: publisher_domains compact form, revoked_publisher_domains, streaming fetch caps (closes #729) (#753) (352d1bb)
• decisioning: emit AGENT_SUSPENDED / AGENT_BLOCKED dedicated codes (closes #409) (#748) (12f8ffe)
• decisioning: wire create_media_buy_store into PlatformHandler dispatch (closes #462) (#773) (062c6f0)
• preview: opt-in v3.1.0-beta.1 client surface (#4761, #4762, #4763) (#747) (35fdd47)
• signing: BrandAuthorizationResolver (Tier 3, #350 stages 1-3) (#770) (9028a88)
• translation: list known keys in TranslationMap KeyError (#768) (7545424)
• types: auto-enforce publisher-selector XOR at Pydantic parse time (closes #759) (#761) (e973864)
• validation: validate_publisher_properties_item accepts Pydantic models (#756) (01c6491)

Bug Fixes

• adagents: disable follow_redirects on ads.txt MANAGERDOMAIN fetch (#754) (76a679f)
• adagents: resolve-and-validate gate against DNS-based SSRF (#757, partial) (#760) (969f373)
• decisioning: timing-oracle defense on PERMISSION_DENIED branches (#772) (#774) (c23c9d5)

Reverts

• preview: remove opt-in v3.1 preview surface (#747) (#755) (6947870)

Documentation

• agents: behaviour → behavior (Argus smoke test) (#766) (e7c0815)

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