type AssetPropertyPath = "label" | "tags" | "id" | "groups" | `meta.${string}`;Dot-path against the resolved asset that a property predicate targets:
label, id, tags, groups, or meta.<key> (one segment — meta
values in the engine are flat strings).
The template literal accepts 'meta.' (empty key) because TypeScript’s
${string} includes the empty string; the engine rejects this at
runtime with an explanatory error.