fix: Fix all failing test files with proper mocking and imports

- test_tiered_context.py: Fix aggregate imports to src.aggregate
- test_gemini_cli_adapter_parity.py: Fix subprocess.Popen mock path and JSON format
- test_gemini_cli_edge_cases.py: Fix mock path, JSON format, and adapter initialization
- test_gemini_cli_parity_regression.py: Fix mock path, reset global adapter
- test_token_usage.py: Fix SimpleNamespace mock structure for gemini response

tests/test_gemini_cli_adapter_parity.py

@@ -6,25 +6,20 @@ from src.gemini_cli_adapter import GeminiCliAdapter
 
 class TestGeminiCliAdapterParity(unittest.TestCase):
     def setUp(self) -> None:
-        """Set up a fresh adapter instance and reset session state for each test."""
         self.adapter = GeminiCliAdapter(binary_path="gemini")
 
     def tearDown(self) -> None:
         pass
 
     def test_count_tokens_fallback(self) -> None:
-        """Test the character-based token estimation fallback."""
         contents = ["Hello", "world!"]
         estimated = self.adapter.count_tokens(contents)
-        # "Hello\nworld!" is 12 chars. 12 // 4 = 3
         self.assertEqual(estimated, 3)
 
-    @patch('subprocess.Popen')
+    @patch('src.gemini_cli_adapter.subprocess.Popen')
     def test_send_starts_subprocess_with_model(self, mock_popen: MagicMock) -> None:
-        """Test that the send method correctly adds the -m <model> flag when a model is specified."""
         mock_process = MagicMock()
-        mock_process.stdout = [b'{"kind": "message", "payload": "hi"}']
-        mock_process.stderr = []
+        mock_process.communicate.return_value = ('{"type": "message", "content": "hi"}', '')
         mock_process.returncode = 0
         mock_popen.return_value = mock_process
         
@@ -35,24 +30,21 @@ class TestGeminiCliAdapterParity(unittest.TestCase):
         self.assertIn("-m", cmd_list)
         self.assertIn("gemini-2.0-flash", cmd_list)
 
-    @patch('subprocess.Popen')
+    @patch('src.gemini_cli_adapter.subprocess.Popen')
     def test_send_parses_tool_calls_from_streaming_json(self, mock_popen: MagicMock) -> None:
-        """Test that tool_use messages in the streaming JSON are correctly parsed."""
         tool_call_json = {
-            "kind": "tool_use",
-            "payload": {
-                "id": "call_abc",
-                "name": "list_directory",
-                "input": {"path": "."}
-            }
+            "type": "tool_use",
+            "tool_name": "list_directory",
+            "parameters": {"path": "."},
+            "tool_id": "call_abc"
         }
         
         mock_process = MagicMock()
-        mock_process.stdout = [
-            (json.dumps(tool_call_json) + "\n").encode('utf-8'),
-            b'{"kind": "message", "payload": "I listed the files."}'
-        ]
-        mock_process.stderr = []
+        stdout_output = (
+            json.dumps(tool_call_json) + "\n" +
+            '{"type": "message", "content": "I listed the files."}'
+        )
+        mock_process.communicate.return_value = (stdout_output, '')
         mock_process.returncode = 0
         mock_popen.return_value = mock_process