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/storage/adapters/fileSystemStorage.ts

@@ -1251,7 +1251,7 @@ export class FileSystemStorage extends BaseStorage {
    * The key's "/"-separated segments become nested directories and the file is
    * suffixed with `.bin`, e.g. `"graph-lsm/source/sstable-123"` →
    * `<rootDir>/_blobs/graph-lsm/source/sstable-123.bin`. This convention is
-   * shared with cortex's `MmapFileSystemStorage` so native code and the TS layer
+   * shared with cor's `MmapFileSystemStorage` so native code and the TS layer
    * agree on exactly where each blob lives.
    *
    * @param key - The blob key.