feat(copilot): replace custom vote system with PostHog thumb survey

[jul-dan]

Summary

Issue: QOV-1793

Replace custom vote system with PostHog thumb survey with up/down vote and custom feedback when downvote

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

[jul-dan]

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[codecov]

Codecov Report

❌ Patch coverage is 60.00000% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 47.59%. Comparing base (cb488d7) to head (c65865d).

Files with missing lines	Patch %	Lines
...ilot-panel/assistant-message/assistant-message.tsx	60.00%	2 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           staging    #2574      +/-   ##
===========================================
+ Coverage    47.45%   47.59%   +0.14%     
===========================================
  Files         1231     1281      +50     
  Lines        23042    24190    +1148     
  Branches      6849     7170     +321     
===========================================
+ Hits         10934    11513     +579     
- Misses       10045    10486     +441     
- Partials      2063     2191     +128     

Flag	Coverage Δ
unittests	47.59% <60.00%> (+0.14%)	⬆️

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