Unexpected behaviour when adding misconfigured extensions

[alexeyre]

Describe the bug

When adding a misconfigured or broken extension from the goose plugin directory, the extension appears enabled despite potentially not being so. For example, with the filesystem plugin, upon adding the extension it appears enabled despite the user not having configured the placeholder paths. When toggling the extension on and off the user is presented with the expected error toast.

To Reproduce Steps to reproduce the behavior:

1. Go to https://block.github.io/goose/extensions/
2. Click on Install under Filesystem
3. Go to Extensions panel in Goose (if not already open)
4. Note extension appears enabled
5. Toggle extension off and on

Expected behavior Goose throws an error on the initial enabling of the extension, or prompts the user to configure it before attempting to enable it.

Screenshots

Please provide following information:

• OS & Arch: MacOS arm64 26.1 (25B77
• Interface: UI
• Version: v1.12.1
• Extensions enabled: Computer Controller, Extensionmanager, Filesystem (ish), Memory, Todo
• Provider & Model: GitHub Copilot gpt-5-mini