chore: rename to @soulcraftlabs/brainy for Open Brainy on The Source

Prepares the repo for its new home at soulcraftlabs/open-brainy ahead
of the Forgejo transfer: package name, publish registry, release
script, and every install/import reference across docs, src, tests,
examples, and integrations now point at @soulcraftlabs/brainy on
The Source. The npmjs storefront leg and byte-identity pair
verification are stripped from the release script — The Source is
now the only publish target. README gains an Open Brainy explainer
and a registry note for consumers.

@soulcraft/brainy 10.4.2 was the last release under the old name.

src/db/errors.ts

@@ -28,7 +28,7 @@
  *   speculative `with()` overlay; the canonical storage walk only ever answers
  *   "what is live right now."
  *
- * All are exported from the package root (`@soulcraft/brainy`).
+ * All are exported from the package root (`@soulcraftlabs/brainy`).
  */
 
 /**