Function should_dispatch 

fn should_dispatch(state: &Arc<AppState>, event: &Event) -> bool

Phase F.7 dedup gate. Returns true if the event is strictly newer for its key and should be dispatched; false if a higher-or-equal version was already sent.

Mirrors the renderer-side shouldDispatchLauncherEvent. Bounded at 4096 keys with FIFO eviction so a long-running host can’t leak unbounded state. Re-arrival of an evicted key bypasses the host gate but the renderer guard still catches it.

Restart sentinel (codex P1 PR #722 round 1): clear the cache when the launcher’s event_version resets to 1 and any cached entry holds a higher version. Mirrors the renderer guard.