docs: rename the native provider to @soulcraft/cor across public docs and JSDoc

The 3.0 native engine ships as @soulcraft/cor (brainy 8.x <-> cor 3.x are a
version-matched pair); the old @soulcraft/cortex package stays on the 2.x/7.x
line. Public docs and .d.ts-visible comments now name the correct package.
Historical 2.x contract references (e.g. the 2.3.1 read-side fallback) keep
the old name deliberately.

src/indexes/columnStore/ColumnSegmentCursor.ts

@@ -7,7 +7,7 @@
  * Multiple cursors can read the same segment concurrently (e.g. during k-way merge).
  *
  * For the TS baseline, segments are loaded fully into memory and cached via
- * UnifiedCache. The Cortex Rust implementation mmaps the segment file and
+ * UnifiedCache. The Cor Rust implementation mmaps the segment file and
  * indexes into it directly — same read interface, zero-copy access.
  */