Show remaining message count to free users

[luke-quadratic]

Description

• Shows a count of messages to Free users.
• Edits data mode to be a paid feature
  Users already with this mode disabled should remain disabled regardless of being free.

To-do's

• Fix logic for when cancel generating button is bumped up vs in normal position
• Count is off by 1

Test plan

• Count should properly decrement and show correct count
• Count should only show to Free users (start with free and ensure it shows, then upgrade and ensure it's no longer showing)
• Cancel generating button should not overlap count; when on Pro cancel generating should be in its prior position
• "Upgrade now" should work same as "Upgrade to Pro" button from when user gets blocked (open in new tab to team/settings)

[qa-wolf]

QA Wolf here! As you write new code it's important that your test coverage is keeping up.
Click here to request test coverage for this PR!

[github-actions]

Preview - Build, Deploy & Tests-E2E

✅ Build images
✅ Deploy images - Oct 13, 2025 at 04:35 PM UTC - Preview
❌ Tests-E2E - Report

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 89.77%. Comparing base (c76a0e9) to head (6e7496a).

Additional details and impacted files

@@           Coverage Diff           @@
##               qa    #3509   +/-   ##
=======================================
  Coverage   89.77%   89.77%           
=======================================
  Files         437      437           
  Lines       90242    90242           
=======================================
  Hits        81012    81012           
  Misses       9230     9230           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.