gui_client: remove diff mode switch, always use diff mode

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

client/gui_client.py

@@ -31,7 +31,7 @@ from pathlib import Path
 from PyQt5.QtCore import QObject, QTimer, Qt, pyqtSignal
 from PyQt5.QtGui import QColor, QFont
 from PyQt5.QtWidgets import (
-    QApplication, QCheckBox, QComboBox, QFormLayout, QGridLayout, QGroupBox,
+    QApplication, QComboBox, QFormLayout, QGridLayout, QGroupBox,
     QHBoxLayout, QLabel, QLineEdit, QMainWindow, QPushButton, QScrollArea,
     QSizePolicy, QSpinBox, QStatusBar, QTabWidget, QTreeWidget, QTreeWidgetItem,
     QVBoxLayout, QWidget,
@@ -126,17 +126,15 @@ class TcpReader(QObject):
         super().__init__()
         self._sock    = None
         self._running = False
-        self._diff_mode = False
         self._state:  dict = {}
 
-    def connect_to(self, host: str, port: int, diff_mode: bool = False) -> str | None:
+    def connect_to(self, host: str, port: int) -> str | None:
         """Open connection; returns error string or None on success."""
         try:
             self._sock = socket.create_connection((host, port), timeout=5)
             self._sock.settimeout(None)
         except OSError as exc:
             return str(exc)
-        self._diff_mode = diff_mode
         self._state   = {}
         self._running   = True
         threading.Thread(target=self._read_loop, daemon=True).start()
@@ -165,11 +163,8 @@ class TcpReader(QObject):
                     if line:
                         try:
                             data = json.loads(line)
-                            if self._diff_mode:
                             self._state = jay_merge_full(self._state, data)
                             self.message.emit(copy.deepcopy(self._state))
-                            else:
-                                self.message.emit(data)
                         except json.JSONDecodeError:
                             pass
         except OSError:
@@ -217,11 +212,9 @@ class ConnectorTab(QWidget):
         self._port = QSpinBox()
         self._port.setRange(1, 65535)
         self._port.setValue(9999)
-        self._diff_cb = QCheckBox("Diff mode")
         self._load_conn_settings()
         form.addRow("Host:", self._host)
         form.addRow("Port:", self._port)
-        form.addRow(self._diff_cb)
 
         btn_row = QHBoxLayout()
         self._btn = QPushButton("Connect")
@@ -244,10 +237,6 @@ class ConnectorTab(QWidget):
         else:
             self.disconnect_requested.emit()
 
-    @property
-    def diff_mode(self) -> bool:
-        return self._diff_cb.isChecked()
-
     def _save_conn_settings(self):
         try:
             _SETTINGS_PATH.parent.mkdir(parents=True, exist_ok=True)
@@ -258,7 +247,6 @@ class ConnectorTab(QWidget):
                 pass
             data["host"] = self._host.text()
             data["port"] = self._port.value()
-            data["diff_mode"] = self._diff_cb.isChecked()
             _SETTINGS_PATH.write_text(json.dumps(data, indent=2))
         except OSError:
             pass
@@ -270,8 +258,6 @@ class ConnectorTab(QWidget):
                 self._host.setText(data["host"])
             if "port" in data:
                 self._port.setValue(int(data["port"]))
-            if "diff_mode" in data:
-                self._diff_cb.setChecked(bool(data["diff_mode"]))
         except (OSError, json.JSONDecodeError, KeyError, ValueError):
             pass
 
@@ -844,7 +830,7 @@ class MainWindow(QMainWindow):
 
     def _connect(self, host: str, port: int):
         self._plot.clear_data()
-        err = self._reader.connect_to(host, port, self._connector.diff_mode)
+        err = self._reader.connect_to(host, port)
         if err:
             self._connector.set_disconnected(err)
             self._statusbar.showMessage(f"Connection failed: {err}")