ci: run test coverage on CLI package

[fabiovincenzi]

Fixes #1331.
This PR is based on #1499 and should be merged after it.

• Add c8 to capture test coverage from CLI subprocess executions
• Add test-coverage-ci script to CLI workspace so --workspaces --if-present picks it up
• Add CLI build step to CI workflow

[netlify]

✅ Deploy Preview for endearing-brigadeiros-63f9d0 canceled.

Name	Link
🔨 Latest commit	0821c36
🔍 Latest deploy log	https://app.netlify.com/projects/endearing-brigadeiros-63f9d0/deploys/69dcf1aa1e72b70008e2295a

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.21%. Comparing base (ba4f08e) to head (0821c36).
⚠️ Report is 9 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1500      +/-   ##
==========================================
+ Coverage   89.66%   90.21%   +0.55%     
==========================================
  Files          68       69       +1     
  Lines        4869     5511     +642     
  Branches      888      944      +56     
==========================================
+ Hits         4366     4972     +606     
- Misses        485      521      +36     
  Partials       18       18              

☔ 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.

[jescalada]

LGTM, just waiting your reply on #1498 before merging 👍🏼