[JFWooten4]

Overview

• Replace the hand-picked 14-file JavaScript test command with ten independently reported feature suites that run all 53 existing test files, plus new extension contract tests.
• Enforce explicit, one-to-one ownership for each tests/*.test.mjs file so no new regression test is accidentally skipped.
• Separate JavaScript syntax + suite inventory, feature suites, native-host tests on Linux and macOS, and extension packaging into distinct CI checks.
• Include the previously undiscovered tests/native-enhancer.test.py native concurrency and recovery suite.
• Extend manifest/package checks to icons, toolbar assets, web-accessible resources, and HTTPS-scoped content scripts; test MIME handler, CSP, integration scope, and accessibility labels.
• Document CI coverage, commands, and the remaining need for live Chrome/Brave browser smoke tests.

Local verification

npm install
npm test
npm run test:feature -- footnotes
npm run check:suites
npm run check:syntax
npm run build && npm run check
python3 -m unittest discover -s tests -p 'test_*.py' -v
python3 tests/native-enhancer.test.py -v

The new matrix's first GitHub Actions execution will validate the previously skipped suites. CI failures should be fixed rather than dropping feature coverage.