feat(auth): add TypeScript types for documented JWT claims fields

[SumitKumar-17]

• Added type safety for email, phone, user_metadata, app_metadata, is_anonymous, etc.
• Provides autocomplete and type safety for all documented JWT claims fields
• getClaims() method now returns properly typed JwtPayload with documented fields

Fixes #1584

🔍 Description

What changed?

Why was this change needed?

Closes #(issue_number)

📸 Screenshots/Examples

🔄 Breaking changes

• This PR contains no breaking changes

📋 Checklist

• I have read the Contributing Guidelines
• My PR title follows the conventional commit format: <type>(<scope>): <description>
• I have run npx nx format to ensure consistent code formatting
• I have added tests for new functionality (if applicable)
• I have updated documentation (if applicable)

📝 Additional notes

[mrbjjackson]

@SumitKumar-17 I'm not sure if this is the correct place to point this out but I'm just looking at your commit - I see you've added an "id" field. I'm not sure where this would come from. It's not mentioned in the docs as far as I can see - rather the claims object uses the "sub" parameter for the user's uuid.

[coveralls]

coverage: 95.455% (-0.5%) from 95.987%
when pulling 905f6a3 on SumitKumar-17:feat/typescript-jwt-claims
into 46abe0d on supabase:master.