LIBAPPPORT-84 Fix Coveralls consistency and add branch coverage

[Janell-Huyck]

Summary

This PR fixes inconsistent Coveralls results and aligns coverage reporting so that only GitHub Actions reports to Coveralls, with an explicit LCOV path/format. We report line coverage only so the badge compares fairly to the qa branch baseline.

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Why results were inconsistent

1. Wrong service name
   .coveralls.yml had service_name: circleci while we run CI on GitHub Actions. Coveralls was attributing builds to the wrong service, which can change how it matches jobs, branches, and “latest” coverage and lead to fluctuating or misleading numbers.

2. No explicit path or format for the coverage file
   The Coveralls GitHub Action was not told where to find the LCOV file or that it was LCOV. It had to guess, and path resolution (e.g. relative vs workspace) can vary. That could cause some runs to find and upload the file and others to miss it or use the wrong format, producing inconsistent coverage.

3. Unreliable LCOV generation in CI
   SimpleCov only writes coverage/lcov.info when ENV['CI'] is set. We weren’t setting CI explicitly in the workflow, so we depended on GitHub’s default. Making it explicit (CI: true in the test step) guarantees the LCOV file is always written in CI.

4. Two CI systems both trying to report coverage
   CircleCI still had a Coveralls orb and an upload step pointing at a path we don’t use (coverage/lcov/application_portfolio.lcov). Our SimpleCov config writes a single file at coverage/lcov.info, so that CircleCI step could never find the right file. Having two CIs (only one of which we actually use for coverage) and a wrong path added noise and inconsistency.

5. Comparing different metrics
   We briefly enabled branch coverage, which reports a stricter (lower) percentage than line coverage. That made this branch look like a ~3% drop vs qa, which reports line coverage. We reverted to line coverage only so the badge compares apples-to-apples with qa.

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Changes made

Area	Change
SimpleCov (spec/spec_helper.rb)	Report line coverage only (no branch coverage) so Coveralls matches the qa baseline. In CI use MultiFormatter (LCOV + HTML) so we get both lcov.info for Coveralls and coverage/index.html for viewing; locally set HTMLFormatter explicitly so index.html is always generated.
GitHub Actions (.github/workflows/main.yml)	Set CI: true in the “Run tests” step so SimpleCov always writes LCOV in CI. Gave the Coveralls step explicit path-to-lcov: ${{ github.workspace }}/coverage/lcov.info and format: lcov.
.coveralls.yml	Updated service_name from circleci to github so builds are attributed to GitHub (Actions).
CircleCI (.circleci/config.yml)	Removed the Coveralls orb, COVERALLS_PARALLEL, and the coveralls/upload step. Coverage is now reported only from GitHub Actions; CircleCI no longer uploads to Coveralls.
README	Clarified that coverage is uploaded automatically from GitHub Actions and updated local instructions to bundle exec rspec and bundle exec rubocop -a (removed the obsolete coveralls report reference).

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Result

• Single source of truth: Only GitHub Actions reports to Coveralls.
• Stable upload: Explicit LCOV path and format so the action always finds and sends the same file.
• Correct service: Coveralls sees builds as github, so branch/PR and “latest” coverage should be consistent.
• Comparable to qa: Line coverage only, so the badge is comparable to the qa branch baseline (no false “drop” from branch coverage).
• Local HTML report: coverage/index.html is always generated (in CI and locally).

After merging, coverage on Coveralls should stabilize and reflect the GitHub Actions test run for each push.

[Janell-Huyck]

turns out the problem was that "branch coverage" drops the coverage % by 3%. Fixed in other PR and we're good.