fix: add pytest.ini with asyncio_mode=auto

- Add pytest.ini configuration file
- Set asyncio_mode=auto for pytest-asyncio
- Enables automatic detection of async test functions
- No need for @pytest .mark.asyncio decorators

Resolves: async def functions are not natively supported

pytest.ini

@@ -0,0 +1,25 @@
+[pytest]
+# pytest-asyncio configuration
+asyncio_mode = auto
+
+# Test discovery patterns
+python_files = test_*.py *_test.py
+python_classes = Test*
+python_functions = test_*
+
+# Coverage settings
+addopts = 
+    --verbose
+    --strict-markers
+    --tb=short
+    --cov-report=term-missing
+
+# Test paths
+testpaths = backend/tests backend
+
+# Markers for test categorization
+markers =
+    slow: marks tests as slow (deselect with '-m "not slow"')
+    integration: marks tests as integration tests
+    unit: marks tests as unit tests
+    e2e: marks tests as end-to-end tests