Derive Macro Observable 

#[derive(Observable)]
{
    // Attributes available to this derive:
    #[obs]
    #[model]
}

Per-property observation for a struct; see day-model’s crate docs and docs/model.md.

Generates typed field accessors on every Source of the struct (store.name(), store.elem(id).name(), nested item.address().city()), Identified from the field marked #[obs(key)] (always explicit), and OBSERVED_FIELDS. #[obs(skip)] leaves a field out, with no accessor, path or trigger.

#[model(…)] attributes are accepted, so a struct can swap this derive for day-persistence’s Model per target: #[model(id)] marks the key and the rest is ignored.