feat!: le paquet crée un index et lui ajoute une référence, rien de plus

src/sparql.ts

@@ -1,5 +1,6 @@
 /**
- * The SPARQL this layer writes — and it writes only one kind of statement.
+ * The SPARQL this layer writes — one statement, and one use for it: the field an
+ * index declares, written on the index document's own subject at creation.
  *
  * There is NO delete builder, and there must not be one: an index never removes
  * an entry, and the surest way to keep that true is for this package to be unable
@@ -61,7 +62,7 @@ export function escapeIri(value: string): string {
 
 /**
  * One triple, for the ANCHORED default graph. The only statement this package
- * ever writes.
+ * ever writes, and it writes it once per index.
  *
  * No `GRAPH <…>` wrapper, and the document is not a parameter at all: it is named
  * once, as `docs.sparqlUpdate`'s anchor, which already scopes the write to that