Add comprehensive test suite (371 tests)

- test_hargen: HAR parsing, schema inference, analyzer grouping, code generation
- test_apkmap: Scanner regex patterns (Retrofit, OkHttp, Flutter, generic URL/auth)
- test_botwall: All 6 detectors with mock response data (headers, cookies, body)
- test_ja3probe: Fingerprint profiles, challenge detection, result analysis
- test_schemadiff: Schema inference, merging, comparison, field similarity, code gen

All tests are self-contained with inline test data, no network access needed.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: b-erdem