Function optimistic

optimistic(
    handlers: Record<
        string,
        { apply: (cmd: Command) => (() => void) | null },
    >,
): Plugin
Optimistic update plugin - apply optimistic state, rollback on failure.

Accepts per-action apply functions that optimistically mutate state and return a rollback closure. If the handler (or async resolution) fails, the rollback is called automatically.
Parameters
- handlers: Record<string, { apply: (cmd: Command) => (() => void) | null }>
Returns Plugin
Example
```
bus.use(optimistic({
  cartAdd: { apply: (cmd) => { addItem(cmd.target); return () => removeItem(cmd.target); } },
}));
```
- Defined in plugins-core.ts:260