The adapters chapter says `<seam>.backend` selects each seam's backend, oracle included; the agent catalog says `oracle.backend` routes nothing.

The adapters chapter says <seam>.backend selects each seam's backend, oracle included; the agent catalog says oracle.backend routes nothing.

A premise contradiction (severity minor) found by the cross-document consistency pass.

• End A: .abcd/development/brief/05-internals/02-adapters.md:28 — ".abcd/config.json → <seam>.backend selects the backend;"
• End B: .abcd/development/brief/05-internals/01-agents.md:204 — "host-delegated, and routes nothing: host-delegated is the only value with an"

02-adapters states that .abcd/config.json → <seam>.backend selects the backend, host-delegated being only the oracle seam's default, so a different value would pick another backend. 01-agents states that oracle.backend records a choice and routes nothing, and the concrete oracle routes go through oracle.roles, roles.<role>.runner and oracle.review instead. Setting oracle.backend either changes routing or it does not.

Evidence: .abcd/work/reviews/2026-10-26-consistency/00-summary.md, finding 778.