build(sdk): publish @punktfunk/host to the Gitea npm registry

- package.json: drop private; point main/types/exports/bin at a tsc-built dist/;
  add publishConfig (unom/npm registry), files, repo metadata, and the
  MIT OR Apache-2.0 license; effect becomes a peerDependency (shared instance).
- tsconfig.build.json: emit dist/ JS + .d.ts (bun shebang preserved on the bin).
- .npmrc: map the @punktfunk scope to the registry (no token committed).
- sdk-publish.yml: publish on sdk-v* tags or manual dispatch, reusing the
  REGISTRY_TOKEN secret; typecheck/test/build/tag-matches-version gate.
- README: Install section for consumers.

Verified: build green, frozen lockfile stable, bun publish --dry-run packs
@punktfunk/host@0.1.0 (dist + README only) to the unom registry.

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

sdk/bun.lock

@@ -4,18 +4,19 @@
   "workspaces": {
     "": {
       "name": "@punktfunk/host",
-      "dependencies": {
-        "effect": "^4.0.0-beta.98",
-      },
       "devDependencies": {
         "@effect/openapi-generator": "4.0.0-beta.98",
         "@effect/platform-node": "4.0.0-beta.98",
         "@types/bun": "^1.3.0",
+        "effect": "^4.0.0-beta.98",
         "typescript": "^5.9.3",
       },
       "optionalDependencies": {
         "undici": "^7.0.0",
       },
+      "peerDependencies": {
+        "effect": "^4.0.0-beta.98",
+      },
     },
   },
   "packages": {