feat: complete client runtime foundation

tests/test_protocol_and_probes.py

@@ -3,7 +3,7 @@ import tempfile
 import unittest
 from pathlib import Path
 
-from archive_clients.probes import probe_root
+from archive_clients.probes import probe_root, probe_writable_directory
 from archive_clients.protocol import ProtocolError, decode, encode, new_envelope
 
 
@@ -26,6 +26,9 @@ class ProtocolAndProbeTests(unittest.TestCase):
             result = probe_root(root)
             self.assertTrue(result.readable)
             self.assertTrue(result.writable)
+            self.assertIsInstance(result.reflink, bool)
+            self.assertEqual(list(root.iterdir()), [])
+            probe_writable_directory(root)
             self.assertEqual(list(root.iterdir()), [])