Toasts require the surreal JS library

[lnoor]

Issue Type

• [ x] Existing documentation (e.g. typos, errors, outdated information)
• Suggest new documentation that is currently missing

Current Behavior or Documentation Gaps
When using toasts the surreal package MUST be included otherwise toasts won't work.
This is not documented and using app = FastHTML(surreal=False,...) toasts failed to show.
Please include this dependency in the description of the toast functionality.

Relevant Links
Toast documentation

Confirmation
Please confirm the following:

• [x ] I have checked the existing issues and pull requests to ensure this documentation issue hasn't been reported before.
• I have read the project's documentation and am confident this issue or suggestion is valid.