…tility-Protocol#56)

Schedules up to 1,000 recurring contract executions with ms precision that keeps
firing while the tab is throttled, via a Web Worker ticking on a SharedArrayBuffer.

- types/scheduler.ts: wheel invariants (1024 slots x 100ms, 1000-job cap, +/-50ms
  tolerance, 200ms fallback), job/meta/status types, SAB Int32 layout, worker
  protocol
- utils/sharedBuffer.ts: SharedArrayBuffer creation + atomic drift/heartbeat/
  command helpers, availability check (COOP/COEP), futexWait/notify with
  non-shared fallback
- utils/timerWheelCore.ts: pure hashed wheel (rounds + pending set so sub-slot
  jobs are never skipped); schedule/cancel/advance with recurrence, drift
  correction, missed-fire detection, and the 1000-job cap
- workers/timerWheel.worker.ts: holds the wheel, sleeps each tick on
  Atomics.wait(HEARTBEAT, 100ms) (timed-loop fallback), advances and posts fired
  jobs; command channel via postMessage + Atomics.notify
- services/timerWheel.ts: main-thread facade — worker path or 200ms polling
  fallback, requestAnimationFrame drift loop writing correction while hidden
- hooks/useScheduledExecution.ts: wraps the service, mirrors metadata to the
  store, auto-cancels on unmount
- store/slices/scheduleSlice.ts: job metadata (next fire, status, missed count)
- components/dashboard/SchedulerDashboard.tsx: jobs table + cancel (component
  rather than src/pages since this is an App Router project)
- tests for the wheel (ordering, rounds, recurrence, cancel, cap, precision,
  drift), the atomic buffer helpers, and the schedule store