Add CloudXR VR streaming support for PICO 4 Ultra (Early Access)

Replaces manual H264/TCP stereo streaming with NVIDIA CloudXR for
higher-quality stereoscopic rendering and lower latency.

Changes:
- teleop_xr_agent.py: add --cloudxr flag (enables Isaac Sim XR mode,
  disables manual StreamingManager)
- deps/cloudxr/: NVIDIA CloudXR.js SDK (Early Access) with Isaac Lab
  teleop React web client
- deps/cloudxr/Dockerfile.wss.proxy: HAProxy WSS proxy for PICO 4 Ultra
  HTTPS mode (routes wss://48322 → ws://49100)
- deps/cloudxr/isaac/webpack.dev.js: disable file watching to avoid
  EMFILE errors with large node_modules
- deps/cloudxr/INSTALL.md: full setup guide

Usage:
  # Start CloudXR Runtime + Isaac Lab
  cd ~/IsaacLab && ./docker/container.py start \
      --files docker-compose.cloudxr-runtime.patch.yaml \
      --env-file .env.cloudxr-runtime

  # Run teleop with CloudXR
  ~/IsaacLab/isaaclab.sh -p teleop_xr_agent.py \
      --task Isaac-MindRobot-2i-DualArm-IK-Abs-v0 --cloudxr

  # Serve web client
  cd deps/cloudxr/isaac && npm run dev-server:https

deps/cloudxr/simple/webpack.common.js

@@ -0,0 +1,41 @@
+const path = require('path');
+const HtmlWebpackPlugin = require('html-webpack-plugin');
+
+module.exports = {
+    entry: './src/main.ts',
+    
+    // Module rules define how different file types are processed
+    module: {
+        rules: [
+            {
+                test: /\.tsx?$/,
+                use: 'ts-loader',
+                exclude: /node_modules/,
+            },
+        ],
+    },
+    
+    // Resolve configuration for module resolution
+    resolve: {
+        extensions: ['.ts', '.js'],
+        alias: {
+            // @helpers can be used instead of relative paths to the helpers directory
+            '@helpers': path.resolve(__dirname, '../helpers')
+        }
+    },
+    
+    // Output configuration for bundled files
+    output: {
+        filename: 'bundle.js',
+        path: path.resolve(__dirname, './build'),
+    },
+    
+    // Webpack plugins that extend webpack's functionality
+    plugins: [
+        // Generates HTML file and automatically injects bundled JavaScript
+        new HtmlWebpackPlugin({
+            template: './index.html',
+            favicon: './favicon.ico'
+        })
+    ]
+};