build: publish @insignia/iios-* SDKs to the Gitea package registry

- .npmrc routes the @insignia scope to https://git.lynkedup.cloud/api/packages/insignia/npm/
  (auth via ${GITEA_TOKEN} env — no secret committed).
- The 9 frontend SDK packages (contracts, kernel-client, adapter-sdk, *-web) are now
  publishable: private dropped, version 0.1.0, publishConfig pinned to Gitea. iios-service
  and iios-testkit stay private (pnpm publish skips them).
- Root `release` / `release:dry` scripts; a Gitea Actions workflow publishes on a v* tag.
- PUBLISHING.md documents publish + consumer (.npmrc) setup.

Verified: dry-run packs cleanly and workspace:* deps resolve to 0.1.0 in the tarball.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.npmrc

@@ -0,0 +1,6 @@
+# @insignia SDK packages publish to / install from the Gitea package registry.
+# Auth comes from the GITEA_TOKEN env var (never commit the token itself).
+#   publish  → token needs the `write:package` scope
+#   install  → token needs `read:package`
+@insignia:registry=https://git.lynkedup.cloud/api/packages/insignia/npm/
+//git.lynkedup.cloud/api/packages/insignia/npm/:_authToken=${GITEA_TOKEN}