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/types/brainy.types.ts

@@ -215,7 +215,7 @@ export interface ScoreExplanation {
  *
  * @example
  * ```ts
- * declare module '@soulcraft/brainy' {
+ * declare module '@soulcraftlabs/brainy' {
  *   interface SubtypeRegistry {
  *     // For NounType.Person, subtype 'employee':
  *     'person:employee': { employeeId: string; department: string }