Studio: Disable text input if the limit is reached UI and update to new headers

[kozer]

Fixes https://github.com/Automattic/dotcom-forge/issues/7420

Proposed Changes

This PR updates the app to use the new quota headers. It is also use those quotas to disable user input

Testing Instructions

• Apply the following diff:

  
  index 282b02a..9a119e1 100644
  --- a/src/hooks/use-prompt-usage.tsx
  +++ b/src/hooks/use-prompt-usage.tsx
  @@ -46,7 +46,7 @@ export function PromptUsageProvider( { children }: PromptUsageProps ) {
                              return;
                      }
                      setPromptLimit( limit );

• setPromptCount( limit - remaining );
• setPromptCount( limit ); if ( ! initiated ) { setInitiated( true ); }

  
  2. Navigate to Assistant tab.
  3. Ensure that input is disabled.

Pre-merge Checklist

• [ ] Have you checked for TypeScript, React or other console errors?

[matt-west]

@jeroenpf @kozer We have some designs for that here.

[kozer]

@matt-west , @jeroenpf I'll create a new ticket for the designs, as now that the old HEAD request is missing it "breaks" Studio app.

[kozer]

Created https://github.com/Automattic/dotcom-forge/issues/7761