test: add VCR.py fixture for HTTP interaction recording

tests/fixtures/vcr.py

@@ -0,0 +1,70 @@
+import pytest
+from pathlib import Path
+
+@pytest.fixture(scope="module")
+def vcr_config():
+    """Configure VCR.py for recording HTTP interactions.
+    
+    This fixture sets up VCR.py with:
+    - YAML serialization
+    - Cassette storage in fixtures/recordings
+    - Comprehensive header filtering for API keys and sensitive data
+    - Request matching on URI, method, and body
+    """
+    # Define cassette storage location
+    vcr_cassettes = Path(__file__).parent / "fixtures" / "recordings"
+    vcr_cassettes.mkdir(parents=True, exist_ok=True)
+
+    # Define sensitive headers to filter
+    sensitive_headers = [
+        # Generic API authentication
+        ("authorization", "REDACTED"),
+        ("x-api-key", "REDACTED"),
+        ("api-key", "REDACTED"),
+        ("bearer", "REDACTED"),
+
+        # LLM service API keys
+        ("openai-api-key", "REDACTED"),
+        ("anthropic-api-key", "REDACTED"),
+        ("cohere-api-key", "REDACTED"),
+        ("x-cohere-api-key", "REDACTED"),
+        ("ai21-api-key", "REDACTED"),
+        ("x-ai21-api-key", "REDACTED"),
+        ("replicate-api-token", "REDACTED"),
+        ("huggingface-api-key", "REDACTED"),
+        ("x-huggingface-api-key", "REDACTED"),
+        ("claude-api-key", "REDACTED"),
+        ("x-claude-api-key", "REDACTED"),
+
+        # Authentication tokens
+        ("x-api-token", "REDACTED"),
+        ("api-token", "REDACTED"), 
+        ("x-auth-token", "REDACTED"),
+        ("x-session-token", "REDACTED"),
+
+        # OpenAI specific headers
+        ("openai-organization", "REDACTED"),
+        ("x-request-id", "REDACTED"),
+        ("__cf_bm", "REDACTED"),
+        ("_cfuvid", "REDACTED"),
+        ("cf-ray", "REDACTED"),
+
+        # Rate limit headers
+        ("x-ratelimit-limit-requests", "REDACTED"),
+        ("x-ratelimit-limit-tokens", "REDACTED"), 
+        ("x-ratelimit-remaining-requests", "REDACTED"),
+        ("x-ratelimit-remaining-tokens", "REDACTED"),
+        ("x-ratelimit-reset-requests", "REDACTED"),
+        ("x-ratelimit-reset-tokens", "REDACTED"),
+    ]
+
+    return {
+        # Basic VCR configuration
+        "serializer": "yaml",
+        "cassette_library_dir": str(vcr_cassettes),
+        "match_on": ["uri", "method", "body"],
+        "record_mode": "once",
+
+        # Header filtering
+        "filter_headers": sensitive_headers,
+    }