Add Invisible SDK Node server example

.env.example

@@ -0,0 +1,7 @@
+NODE_AUTH_TOKEN=github_pat_with_read_packages
+PORT=8787
+INVISIBLE_COORDINATOR_PRESET=dev
+INVISIBLE_ENABLE_MUTATIONS=false
+
+# Optional: pass an exact CoordinatorPoolConfig JSON instead of a preset.
+# INVISIBLE_COORDINATOR_POOL_JSON={"endpoints":[{"wsUrl":"wss://example.com/ws-noise","expectedHostname":"example.com","releasePin":{"mrtd":"..."},"requiredMode":"prod"}]}

.gitignore

@@ -1,7 +1,6 @@
 node_modules/
 dist/
-.wrangler/
 .env
 .env.*
-!.dev.vars.example
+!.env.example
 *.tsbuildinfo

.npmrc

@@ -0,0 +1,2 @@
+@invisible-labs:registry=https://npm.pkg.github.com
+save-exact=true

README.md

@@ -1,5 +1,51 @@
-# Invisible Worker
+# Invisible SDK Node Server Example
 
-Cloudflare Worker server example for Invisible private transfers.
+Backend/server example for `@invisible-labs/sdk`.
 
-Implementation lives in pull requests.
+This replaces the old "worker" positioning with a standard Node.js HTTP server.
+
+It demonstrates the current SDK basics:
+
+- attested session open, re-attestation, close
+- normal-user private transfer, status restore, refund intent
+- LP lifecycle entrypoints: create, recover, DKG, funding, refill, withdraw
+- local storage, recovery-code helpers, derived refundable amount
+- coordinator-pending surfaces are imported and kept explicit
+
+## Install
+
+The SDK is currently private on GitHub Packages.
+
+```bash
+export NODE_AUTH_TOKEN=<github-token-with-read:packages>
+npm ci
+```
+
+If npm is not already configured for GitHub Packages:
+
+```bash
+npm config set //npm.pkg.github.com/:_authToken "$NODE_AUTH_TOKEN"
+```
+
+## Run
+
+```bash
+cp .env.example .env
+npm run dev
+```
+
+Safe routes:
+
+- `GET /health`: local SDK utility check
+- `GET /sdk/surface`: SDK surface imported by this example
+- `POST /attestation`: opens and closes an attested SDK session
+
+Mutating routes are blocked unless `INVISIBLE_ENABLE_MUTATIONS=true`.
+
+## Validate
+
+```bash
+npm run typecheck
+npm run build
+npm test
+```