feat(user-settings): add console preference toggle to user-modal and implement legacy console redirection logic

[RemiBonnet]

Summary

Add toggle to redirect in the legacy console if needed under a ff

Screenshots / Recordings

Testing

• Changes tested locally in the relevant Console's pages and Storybooks
• yarn test or yarn test -u (if you need to regenerate snapshots)
• yarn format
• yarn lint

PR Checklist

• I followed naming, styling, and TypeScript rules (see .cursor/rules)
• I performed a self-review (diff inspected, dead code removed)
• I titled the PR using Conventional Commits with a scope when possible (e.g. feat(service): add new Terraform service) - required for semantic-release
• I only kept necessary comments, written in English (watch for useless AI comments)
• I involved a designer to validate UI changes if I am not a designer
• I covered new business logic with tests (unit)
• I confirmed CI is green (Codecov red can be accepted)
• I reviewed and executed locally any AI-assisted code

[codecov]

Codecov Report

❌ Patch coverage is 80.00000% with 3 lines in your changes missing coverage. Please review.
⚠️ Please upload report for BASE (new-navigation@c551af3). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
...rc/lib/user-settings-modal/user-settings-modal.tsx	66.66%	1 Missing and 2 partials ⚠️

Additional details and impacted files

@@                Coverage Diff                @@
##             new-navigation    #2614   +/-   ##
=================================================
  Coverage                  ?   44.92%           
=================================================
  Files                     ?      719           
  Lines                     ?    17314           
  Branches                  ?     5120           
=================================================
  Hits                      ?     7779           
  Misses                    ?     8154           
  Partials                  ?     1381           

Flag	Coverage Δ
unittests	44.92% <80.00%> (?)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ 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.

[rmnbrd]

LGTM