browser subagent fails in wayland

### What happened?

browser subagnet fails

```
Browser Agent Finished │
│ │
│ Termination Reason: GOAL │
│ │
│ Result: │
│ { │
│ "success": false, │
│ "summary": "Terminal Failure: Failed to open a new page. The browser implementation returned the │
│ following error: \"Missing X server to start the headful browser. Either set headless to true or use │
│ xvfb-run to run your Puppeteer script.\" This error appears unrecoverable as I do not have direct │
│ control over the browser's launch parameters (e.g., setting headless=true) through the available │
│ tools. According to the instructions, this is a terminal failure. Please check the browser │
│ configuration or try again." │
│ } │
│
```

### What did you expect to happen?

I expected it to not error, I'm using wayland , if the gui is not possible atleast it should fallback to headless

### Client information

Client Information

Run `gemini` to enter the interactive CLI, then run the `/about` command.

```console
> /about
About Gemini CLI │
│ │
│ CLI Version 0.33.0 │
│ Git Commit 6ee19e1f6 │
│ Model Auto (Gemini 3) │
│ Sandbox no sandbox │
│ OS linux │
│ Tier Gemini Code Assist for individuals │
│ │
╰─────────────────────
```

### Login information

_No response_

### Anything else we need to know?

_No response_