Bevy 0.19 — save and load

When to use this skill

• Gameplay state must remain loadable across ECS/content/code refactors.
• Large worlds need base snapshots, sparse deltas, compaction, and recovery.
• Native and browser builds need one asynchronous save-service contract.
• Reflected world serialization is being considered as a durable save format.

A save file is a long-lived product API. Serialize an explicit, versioned data model and convert it to/from the live ECS. Runtime Entity values, dense palette indices, query order, Rust enum discriminants, and reflected component layout are not stable persistence identities.

Canonical pattern

use serde::{Deserialize, Serialize};