fix(browser): use Extended Pro label for ChatGPT Pro picker since GPT-5.4 Pro no longer works

[seichris]

Cherry-picks steipete#122 into this fork.

Summary

• map ChatGPT Pro browser targets to the current label
• update the default browser target string to the same label
• adjust the browser-config tests accordingly

Why

The live ChatGPT picker no longer exposes ; it exposes .
Oracle's browser config was still emitting the old label, so browser runs targeting Pro failed at model selection.

Validation

• upstream PR notes:

@steipete/oracle@0.9.0 test /Users/chris/Documents/Workspace/oracle-bundle-into-chatgpt
vitest run "tests/cli/browserConfig.test.ts" "tests/browser/modelSelection.test.ts"

 ELIFECYCLE  Test failed. See above for more details.
 WARN  Local package.json exists, but node_modules missing, did you mean to install?

• not rerun in this checkout because local dependencies are not installed