Per-agent x64dbg session through debugger()/debugger_tools()

Harbor starts the x64dbg-automate MCP server (stdio) on first use and keeps
it for the life of the agent's Harbor process; the debuggee is terminated
when that process exits. Configured by debugger_command/_path/_temp in
[reverse].

tests/test_reverse.py

@@ -117,3 +117,22 @@ class GhidraForwarder(unittest.TestCase):
         with self.assertRaises(HarborError):
             from harbor.reverse import Ghidra
             Ghidra({"ghidra_url": "http://127.0.0.1:9/mcp"}).tools()
+
+
+class DebuggerForwarder(unittest.TestCase):
+    """debugger() keeps one stdio MCP server per Harbor process and skips its notifications."""
+
+    def test_call_and_error(self):
+        import sys
+        from pathlib import Path
+        from harbor.reverse import Debugger
+        d = Debugger({"debugger_command": [sys.executable, "-B", str(Path(__file__).with_name("fake_stdio_mcp.py"))]})
+        try:
+            self.assertEqual(d.tools()[0]["name"], "echo")
+            self.assertEqual(d.call("echo", {"x": 1}), 'echo {"x": 1}')
+            with self.assertRaises(HarborError):
+                d.call("terminate_session")
+        finally:
+            d.close()
+        with self.assertRaises(HarborError):
+            Debugger({})