- Add browser-compatible test files (no npm required)
- recorder.test.browser.js: 8 tests for microphone and HTTP detection
- tools.test.browser.js: 5 tests for Live2D actions and error handling
- Add test runner (test-runner.html) with built-in test framework
- Add null safety checks in tools.js for DOM element access
- Add documentation (English and Chinese versions)
- README_TESTS.md / README_TESTS_CN.md: Complete test guide
- QUICK_START_TEST.md / QUICK_START_TEST_CN.md: Quick start guides
- Total: 13 unit tests covering microphone detection, HTTP detection, Live2D actions, and error handling