fix: Address code review feedback

- Added explanation for logger mocking in tests/setup.ts
- Removed test files from coverage collection in jest.config.js
- Updated tests/README.md to clarify coverage approach and remove outdated threshold reference

Co-authored-by: mindesbunister <32161838+mindesbunister@users.noreply.github.com>

tests/setup.ts

@@ -33,6 +33,10 @@ declare global {
 }
 
 // Mock logger to reduce noise during tests
+// Logger is mocked to:
+// 1. Prevent console output during test runs
+// 2. Isolate tests from external I/O operations
+// 3. Enable verification of logging calls if needed
 jest.mock('../lib/utils/logger', () => ({
   logger: {
     log: jest.fn(),