[Bug]: Browser settings changed in project scope silently overwrite the global default #35093

Version: T3 Code (Beta) 0.1.9 (24e77473ecf4), macOS desktop

What happened

In Settings → Browser, with the scope set to a single project, changing Default browser viewport does not create a project override. It silently changes the global default for all projects. There is no warning or disabled state.

Steps to reproduce

1. Settings → Browser, scope All: set the default viewport to Fill pane.
2. Switch the scope to Project A: set it to Responsive 1440 × 900.
3. Switch back to scope All, or open a browser tab in Project B.

Expected: Either a real project override, or (if not supported) the control is disabled in project scope with the usual "cannot be overridden by a project" hint.
Actual: The global value (browserDefaultViewport in client-settings.json) is now 1440 × 900 for every project.

Cause (from the shipped bundle)

• browserDefaultViewport is a client setting. The project override schema (projectSettingsOverrides) only accepts server keys (defaultModelSelection, defaultRuntimeMode, enableAgentBrowserAccess, …).
• The settings write path splits a patch into client and server keys. In project/checkout scope only the server keys become a project override. Client keys still go into clientPatch and are written globally, whatever the selected scope.
• "This setting is environment-wide and cannot be overridden by a project." only shows when nothing at all would be written. Because the client write happens, the hint never appears.

Probably the same for the other client-only rows shown in project scope (e.g. default zoom, default appearance), since they take the same path.

Suggested fix

In project/checkout scope, don't write client keys. Show those rows as disabled with the "cannot be overridden by a project" hint, or hide them.

Related

• Browser tabs in the right panel ignore the Integrations default zoom and appearance #24911: browser tabs ignore the global default zoom/appearance (same area, different bug)
• feat(settings): leave environments that can't store a setting out of its row #18361: hides settings rows for environments that can't store a setting (server settings only)