fix(auth): include user timezone in login request

[Suyash-ka-github]

Description

This pull request fixes missing timezone information during user login by sending the browser-detected timezone to the backend.

This ensures backend services (such as analytics) can correctly process user activity based on the user's local timezone instead of UTC.

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Code refactoring
• Performance improvement
• Test addition/update
• Chore/maintenance

Changes Made

• Added browser timezone detection using Intl.DateTimeFormat().resolvedOptions().timeZone
• Included timezone in login API request payload
• Updated login request typing to support timezone field

Testing Done

• Logged in locally using the browser extension
• Verified timezone value is correctly sent to the backend
• Confirmed backend receives and stores timezone without errors

Checklist

• I have read and followed all guidelines in CONTRIBUTING.md
• I have used the correct branch naming convention (feature/, fix/, docs/, etc.)
• My commits follow Conventional Commits format (feat:, fix:, docs:, etc.)
• I have performed a self-review and tested my changes thoroughly
• CRITICAL: I confirm ONLY my intended changes are included (no unrelated changes, debug code, or breaking changes)
• I have updated relevant documentation if needed

Screenshots (if applicable)

N/A (no UI changes)

Additional Notes

This change complements backend timezone handling and enables correct timezone-aware analytics for users across different regions.

Related PRs

Related to: browseping/server#20 - This PR provides the timezone data that the server-side changes consume for timezone-aware analytics. Both PRs should be merged together for complete functionality.

[Suyash-ka-github]

This is the fix for the Timezone Issue I raised on the server Could you please let me know if everthing is fine and good to go

[akash-kumar-dev]

Related to: browseping/server#20