refactor(catalog): explicit org/repo terminology; npm targets coulomb Gitea registry

Gitea's "project/package/release" terms are overloaded, so the catalog now uses
the most explicit words:
- org  = coulomb (the Gitea organisation)
- repo = whynot-design (the Gitea repository/product) — not an org, not a scope
- npm scope @whynot and package @whynot/design are distinct from both

Changes:
- catalog schema: replace conflated `owner` with required `org` + `repo`; `owner`
  is now a derived `org/repo` slug property
- npm-config delivery is data-driven: registry + scope live in
  delivery_config.npm and are validated; engine no longer hardcodes a registry
- exec delivery writes `<scope>:registry=<url>` + scoped `:_authToken` for the
  configured Gitea registry (token still env-expanded, never written to disk)
- pilot lane points at https://gitea.coulomb.social/api/packages/coulomb/npm/,
  scope @whynot, KV path coulomb/whynot-design/npm/publish
- npm-publish-demo uses @whynot scope so dry-run resolves the Gitea registry
- docs: terminology table; routing owner shown as coulomb/whynot-design
- tests: org/repo required, npm-config validation, registry authkey mapping

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

catalog/example-build-test-token.yaml

@@ -1,7 +1,8 @@
 # Example BUILD-stage lane. Demonstrates that build entries can be looser:
 # generated test values are allowed and no production decision is required.
 id: example-build-test-token
-owner: platform-ci
+org: coulomb
+repo: platform-ci
 stage: build
 description: >-
   Throwaway generated credential for build-stage integration tests. May be