refactor(cua-cli): rename 'open' command to 'vnc' with backwards compatibility

Rename the VNC command from 'open' to 'vnc' for clarity and specificity.
Keep 'open' as an alias for backwards compatibility.

Changes:
- Update command definition to use 'vnc' as primary, 'open' as alias
- Update README.md to reflect new command name
- Update commands.mdx documentation with new command and alias
- Update quickstart.mdx to use 'cua sb vnc'
- Update command examples in tips section

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

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

libs/typescript/cua-cli/README.md

@@ -50,7 +50,7 @@ bun run ./index.ts -- --help
   - `start <name>` – start a stopped sandbox
   - `stop <name>` – stop a running sandbox
   - `restart <name>` – restart a sandbox
-  - `open <name>` – open NoVNC URL in your browser
+  - `vnc <name>` (alias: `open`) – open VNC desktop in your browser
 
 ## Auth Flow (Dynamic Callback Port)
 

libs/typescript/cua-cli/src/commands/sandbox.ts

@@ -290,8 +290,8 @@ export function registerSandboxCommands(y: Argv) {
       restartHandler
     )
     .command(
-      'open <name>',
-      'Open NoVNC for a sandbox in your browser',
+      ['vnc <name>', 'open <name>'],
+      'Open VNC desktop for a sandbox',
       (y) => y.positional('name', { type: 'string', describe: 'Sandbox name' }),
       openHandler
     );
@@ -368,8 +368,8 @@ export function registerSandboxCommands(y: Argv) {
           restartHandler
         )
         .command(
-          'open <name>',
-          'Open NoVNC for a sandbox in your browser',
+          ['vnc <name>', 'open <name>'],
+          'Open VNC desktop for a sandbox',
           (y) => y.positional('name', { type: 'string', describe: 'Sandbox name' }),
           openHandler
         )