feat: add unit tests with mocked httpx (28 tests)

- Test request construction, response parsing, error handling
- Mock httpx.Client.request instead of hitting real API
- Test all endpoints: scrape, extract, search, crawl, monitor, history
- Test HTTP errors (401, 402, 429), timeouts
- Test camelCase serialization
- Update CI to run test_client.py

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: FrancescoSaverioZuppichini

.github/workflows/ci.yml

@@ -21,4 +21,4 @@ jobs:
       - uses: actions/checkout@v4
       - uses: astral-sh/setup-uv@v3
       - run: uv sync --frozen
-      - run: uv run pytest tests/ -v --ignore=tests/test_integration.py
+      - run: uv run pytest tests/test_client.py -v

.github/workflows/python-publish.yml

@@ -11,7 +11,7 @@ jobs:
       - uses: actions/checkout@v4
       - uses: astral-sh/setup-uv@v3
       - run: uv sync --frozen
-      - run: uv run pytest tests/ -v --ignore=tests/test_integration.py
+      - run: uv run pytest tests/test_client.py -v
 
   publish:
     needs: test