fix(cutter): attribute the host application version

Identify the Cutter host through Qt applicationVersion rather than the embedded Rizin module-version report. Preserve unknown host metadata without backend fallback and reuse the existing per-plugin lifetime observation.

Validated 13 Python protocol tests, 66 related CLI/MCP/provider tests, full static/docs gates, and official Linux Cutter 2.5.0 Qt5 public workflows. Native discovery and both Evidence version fields match the independently observed host version; source paths and cleanup remain preserved. The named-tool workflow serialization proxy drops from 8767 to 6912 o200k tokens; this is not model billing.

Fixes #4498.

bridge/cutter/rea_bridge.py

@@ -28,9 +28,9 @@ if os.name == "nt":
 import cutter
 
 try:
-    from PySide6.QtCore import QObject, Signal
+    from PySide6.QtCore import QCoreApplication, QObject, Signal
 except ImportError:
-    from PySide2.QtCore import QObject, Signal
+    from PySide2.QtCore import QCoreApplication, QObject, Signal
 
 
 MAX_FRAME_BYTES = 16 * 1024 * 1024
@@ -326,7 +326,8 @@ class _RequestDispatcher(QObject):
         self._receipt_lock = threading.Lock()
         self.current_file = self._read_current_file()
         try:
-            self.cutter_version = str(cutter.core().getVersionInformation())
+            value = QCoreApplication.applicationVersion()
+            self.cutter_version = value if isinstance(value, str) and value else None
         except Exception:
             self.cutter_version = None
 

tests/fixtures/cutter_bridge_protocol_test.py

@@ -24,6 +24,7 @@ def _install_host_stubs():
     qtcore = types.ModuleType("PySide6.QtCore")
     qtcore.QObject = type("QObject", (), {})
     qtcore.Signal = lambda *_args: types.SimpleNamespace(connect=lambda _handler: None)
+    qtcore.QCoreApplication = types.SimpleNamespace(applicationVersion=lambda: "Cutter test host")
     pyside = types.ModuleType("PySide6")
     pyside.QtCore = qtcore
     sys.modules["PySide6"] = pyside
@@ -229,7 +230,6 @@ class DocumentIdentityTest(unittest.TestCase):
         configuration = {"file.path": first}
         core = types.SimpleNamespace(
             getConfig=configuration.__getitem__,
-            getVersionInformation=lambda: "backend fixture",
         )
         commands = []
         with patch.object(bridge.cutter, "core", lambda: core, create=True), patch.object(
@@ -280,6 +280,46 @@ class DocumentIdentityTest(unittest.TestCase):
                 self.assertIsNone(bridge._RequestDispatcher._read_current_file())
 
 
+class HostVersionTest(unittest.TestCase):
+    def test_host_version_reaches_status_and_command_without_backend_attribution(self):
+        backend_reads = []
+        core = types.SimpleNamespace(
+            getConfig=lambda _key: None,
+            getVersionInformation=lambda: backend_reads.append(True) or "Rizin 0.9.1",
+        )
+        application = sys.modules["PySide6.QtCore"].QCoreApplication
+        with patch.object(bridge.cutter, "core", lambda: core, create=True), patch.object(
+            application, "applicationVersion", return_value="2.5.0-HEAD-fixture"
+        ), patch.object(bridge.cutter, "cmd", lambda _command: "observed", create=True):
+            dispatcher = bridge._RequestDispatcher()
+            self.assertEqual(dispatcher.cutter_version, "2.5.0-HEAD-fixture")
+            for values in [
+                {"kind": "status"},
+                {"kind": "command", "request_id": str(uuid.uuid4()), "expected_generation": 0, "command": "iI"},
+            ]:
+                request = {**values, "_event": threading.Event(), "_cancelled": threading.Event()}
+                reply = {}
+                dispatcher._handle(request, reply)
+                self.assertTrue(request["_event"].is_set())
+                self.assertEqual(reply["cutter_version"], "2.5.0-HEAD-fixture")
+            self.assertEqual(backend_reads, [])
+
+    def test_unavailable_host_version_stays_unknown_without_backend_fallback(self):
+        core = types.SimpleNamespace(
+            getConfig=lambda _key: None,
+            getVersionInformation=lambda: "Rizin 0.9.1",
+        )
+        application = sys.modules["PySide6.QtCore"].QCoreApplication
+        with patch.object(bridge.cutter, "core", lambda: core, create=True):
+            for value in ["", None, object()]:
+                with self.subTest(value=type(value).__name__), patch.object(
+                    application, "applicationVersion", return_value=value
+                ):
+                    self.assertIsNone(bridge._RequestDispatcher().cutter_version)
+            with patch.object(application, "applicationVersion", side_effect=RuntimeError("host unavailable")):
+                self.assertIsNone(bridge._RequestDispatcher().cutter_version)
+
+
 class ProtocolProducerTest(unittest.TestCase):
     def test_rejects_legacy_peers_before_ui_dispatch(self):
         with socket.create_connection(("127.0.0.1", self.server.port), timeout=2) as connection: