feat: toast timeout configuration

[kristian-zendato]

Summary

Adds configurable timeouts for ordinary toast notifications.

• Exposes getToastTimeout and setToastTimeout
• Shares the configured value across bundled library copies via window
• Preserves fixed behavior for loading, undo, and permanent toasts

🤖 AI (if applicable)

• The content of this PR was partly or fully generated using AI

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 54.83%. Comparing base (22d789b) to head (0fb0cb1).
⚠️ Report is 8 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff             @@
##             main    #2539       +/-   ##
===========================================
+ Coverage   43.79%   54.83%   +11.03%     
===========================================
  Files          15       15               
  Lines         427      445       +18     
  Branches       82       89        +7     
===========================================
+ Hits          187      244       +57     
+ Misses        211      179       -32     
+ Partials       29       22        -7     

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[susnux]

What would be the use case to expose this?
The values are only used internally by the toast implementation?

[susnux]

I think this is only used internally so the value specified on server should be provided in the capabilities of theming and then used in the implementation here