## Description
Add draggable resize handle to tool list panel with min/max width
constraints, visual feedback, and localStorage persistence.
## PR Checklist
> Thank you for opening a Pull Request! Before submitting your PR, there
are a
> few things you can do to make sure it goes smoothly:
- [ ] Make sure you reviewed
[CONTRIBUTING.md](https://github.com/googleapis/genai-toolbox/blob/main/CONTRIBUTING.md)
- [ ] Make sure to open an issue as a
[bug/issue](https://github.com/googleapis/genai-toolbox/issues/new/choose)
before writing your code! That way we can discuss the change, evaluate
designs, and agree on the general idea
- [ ] Ensure the tests and linter pass
- [ ] Code coverage does not decrease (if any source code was changed)
- [ ] Appropriate docs were updated (if necessary)
- [ ] Make sure to add `!` if this involve a breaking change
🛠️Fixes#1729
---------
Co-authored-by: Wenxin Du <117315983+duwenxin99@users.noreply.github.com>
Add `Sign in with Google` button within Toolbox UI's `Edit Header` modal
that automatically retrieves a valid ID token for users based on an
input clientID.
This should make it significantly easier/faster for users to format
request headers properly and test tools that use auth.
Introduce Toolbox UI, which can be launched with the `--ui` flag.
This initial version of Toolbox UI allows users to test Toolbox by
inspecting tools/toolsets, modifying parameters, managing headers, and
executing API calls.
