feat: complete client runtime foundation

tests/test_logging.py

@@ -0,0 +1,22 @@
+import json
+import logging
+import unittest
+
+from archive_clients.logging_config import RedactingJsonFormatter
+
+
+class LoggingTests(unittest.TestCase):
+    def test_secret_is_redacted_from_message_and_fields(self):
+        formatter = RedactingJsonFormatter(["shared-secret"])
+        record = logging.LogRecord(
+            "test", logging.INFO, __file__, 1,
+            "token=%s", ("shared-secret",), None,
+        )
+        record.error_type = "shared-secret"
+        rendered = formatter.format(record)
+        self.assertNotIn("shared-secret", rendered)
+        self.assertEqual(json.loads(rendered)["error_type"], "[REDACTED]")
+
+
+if __name__ == "__main__":
+    unittest.main()