resetInputState
Cancels pointer capture and clears hover and focused input after window blur or an explicit platform input reset.
This synchronous owner-thread operation preserves the attached session and its committed immutable frame. It is a no-op before the first successful frame, and cancellation clears ownership before callbacks run.
Throws
when called from another thread, reentrantly, or while the session is not attached.
when input cleanup fails; the exact first failure remains primary while remaining cleanup is attempted.