Update for simplified client API and add Node.js hosting guide

Changes:
- Update App.jsx to use Rondevu.connect() instead of new + initialize()
- Update publishService to use 'service' parameter instead of 'serviceFqn'
- Remove explicit claimUsername() calls (now implicit)
- Add comprehensive NODE_HOST_GUIDE.md for hosting WebRTC services in Node.js
- Update README with Node.js hosting section

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

TEST_README.md

@@ -0,0 +1,67 @@
+# Running Node.js Tests
+
+The `test-connect.js` script demonstrates connecting to a Rondevu service from Node.js and sending a WebRTC data channel message.
+
+## Requirements
+
+- Node.js 19+ (or Node.js 18 with `--experimental-global-webcrypto` flag)
+- wrtc package (for WebRTC support in Node.js)
+
+## Installation
+
+The `wrtc` package requires native compilation. Due to build complexities, it's not included as a regular dependency.
+
+### Install wrtc manually:
+
+```bash
+# Install build tools (if not already installed)
+# On Ubuntu/Debian:
+sudo apt-get install build-essential python3
+
+# On macOS:
+xcode-select --install
+
+# Install wrtc
+npm install wrtc
+```
+
+**Note:** Installation may take several minutes as it compiles native code.
+
+### Alternative: Test without WebRTC
+
+If wrtc installation fails, you can still test the signaling layer without actual WebRTC connections by modifying the test script or using the browser demo at https://ronde.vu
+
+## Running the Test
+
+Once wrtc is installed:
+
+```bash
+npm test
+```
+
+This will:
+1. Connect to the production Rondevu server
+2. Look for @bas's chat service
+3. Establish a WebRTC connection
+4. Send "hello" via data channel
+
+## Troubleshooting
+
+### wrtc installation fails
+
+Try installing dependencies:
+```bash
+npm install node-pre-gyp node-gyp
+npm install wrtc
+```
+
+### "crypto.subtle is not available"
+
+You need Node.js 19+ or run with:
+```bash
+node --experimental-global-webcrypto test-connect.js
+```
+
+### Can't find @bas's service
+
+The test looks for `chat:1.0.0@bas`. If @bas is not online or the service expired, the test will fail. You can modify the `TARGET_USER` constant to test with a different user.