[under-undefined]

## Summary

Fixes an infinite render loop in `useRoomState()` / `useColyseusState()` when a selector returns a newly derived root array or plain object.

For example:

```tsx
useRoomState(room, (state) => Array.from(state.players.values()));

useRoomState(room, (state) => ({
  message: state.myString,
}));

Problem

Colyseus Schema, MapSchema, and ArraySchema nodes have stable refId values, allowing createSnapshot() to reuse previous results through resultsByRefId.

Selector-created arrays and objects do not have a Colyseus refId. As a result, every getSnapshot() call produced a new root reference, even when the room state had not changed.

This violates the referential stability requirement of useSyncExternalStore() and causes React to repeatedly render until it throws:

The result of getSnapshot should be cached to avoid an infinite loop
Maximum update depth exceeded

Solution

Add hook-local structural sharing for selector-derived root containers that do not have a Colyseus refId.

The new behavior:

• Reuses the previous root snapshot when its contents are unchanged.
• Creates a new root snapshot when selected data changes.
• Preserves references for unchanged nested values.
• Keeps the existing resultsByRefId behavior unchanged for normal Colyseus Schema roots.
• Keeps selectors operating on the live Colyseus state, preserving APIs such as MapSchema#get() and MapSchema#values().
• Resets reuse boundaries when the room state or decoder changes.

Tests

Added regression coverage for:

• A selector returning a derived root array.
• A selector returning a derived plain object.
• Updating the underlying room state after the derived snapshot has been cached.

[endel]

Hi @under-undefined - thank you for reporting and for sharing the reproduction scenarios - can you please check if version 0.1.19 fixes this for you?

Took a slight different approach to your PR there

[under-undefined]

@endel 0.1.19 Fixed 😊