ci: GitLab-Pipeline - build_embedded + manueller npm-Publish nach rohana (threadnet-call#1)

Registry-Entscheidung evidenzbasiert: das Package ist pnpm-Dependency von
ThreadNet-Webs apps/web, der Lockfile pinnt die Tarball-URL auf rohana -
Registry bleibt dort. Publish-Auth ueber CI-Variable GITEA_NPM_TOKEN statt
lokaler Klartext-.npmrc.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

vite-sdk.config.ts

@@ -0,0 +1,28 @@
+/*
+Copyright 2025 Element Creations Ltd.
+
+SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
+Please see LICENSE in the repository root for full details.
+*/
+
+import { defineConfig, mergeConfig } from "vite";
+import nodePolyfills from "vite-plugin-node-stdlib-browser";
+
+const base = "./";
+
+// Config for embedded deployments (possibly hosted under a non-root path)
+export default defineConfig(() => ({
+  worker: { format: "es" as const },
+  base, // Use relative URLs to allow the app to be hosted under any path
+  build: {
+    sourcemap: true,
+    manifest: true,
+    lib: {
+      formats: ["es" as const],
+      entry: "./sdk/main.ts",
+      name: "MatrixrtcSdk",
+      fileName: "matrixrtc-sdk",
+    },
+  },
+  plugins: [nodePolyfills()],
+}));