Fix rejected steer details ownership

[ymichael]

What was wrong

The lazy expanded-details projection filtered only accepted human steers. Rejected human steers are also root-owned, so a rejected steer spanning a completed work item appeared once in the root timeline and again inside the expanded summary.

What changed

Renamed the shared predicate around the ownership invariant and removed its accepted-status restriction while retaining the human-initiator and steer-kind checks. The persisted-event regression now covers accepted and rejected outcomes and proves each appears once at the root and never in expanded details. No server/daemon wire contract changed; HOST_DAEMON_PROTOCOL_VERSION remains 166.

How you verified

• Red: pnpm exec turbo run test --filter=@bb/server --force -- --run test/services/threads/timeline-in-turn-window.test.ts failed only the new rejected case (25 passed, 1 failed) because details contained the rejected steer.
• Green: the same focused command passed 26/26 tests.
• pnpm exec turbo run test --filter=@bb/thread-view --force passed 368/368 tests.
• pnpm exec turbo run typecheck --filter=@bb/thread-view --filter=@bb/server passed all 5 Turbo tasks.
• Changed-file formatting and git diff --check passed.

Fixes #2378

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