orchestrator platform driver (openprot_orchestrator_driver)

The effect-executing layer around the orchestrator state machine. PlatformDriver implements the SM's Platform seam: one executor per Effect, each documenting its obligation from the platform-boundary contract (orchestrator-model.md §6). An effect whose capability is not composed yet returns EffectError from execute; the SM fail-closes on it.

Everything device-specific arrives through the seams in board.rs (ImageSource, Verifier, BootControl, BootWatch, bundled in Board). Synchronous results (the verification verdict) return through execute and settle within the same dispatch run — there is no driver-side event queue.

Boot-walk verdicts are the one asynchronous read. ReleaseReset arms the component's walk; the run loop polls and dispatches until quiet, then sleeps until the earliest walk deadline:

orch.dispatch(&mut driver, event);
loop {
    let poll = driver.poll_boot_walks(now_millis);
    match poll.event {
        Some(ev) => orch.dispatch(&mut driver, ev),
        None => break, // poll.next_deadline_millis = next wake-up
    }
}

Implemented executors: ReadFirmware, VerifyFirmware, ReleaseReset (arms the boot walk), AssertReset (stops it). Everything else fails closed until its pillar lands (recovery, update path, attestation, reporting, lockdown latch).