Fix TUI apps (mc, htop, vim) freezing in SSH terminal

- Remove LNM mode that corrupted cursor positioning for TUI programs
- Add render debouncing (~60fps) to prevent UI thread blocking
- Add data batching in terminal tab to reduce render calls
- Increase SSH recv buffer from 4KB to 64KB

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

core/ssh_client.py

@@ -114,7 +114,7 @@ class ShellSession:
         try:
             while self._running:
                 try:
-                    data = self._channel.recv(4096)
+                    data = self._channel.recv(65536)
                     if not data:
                         break
                     if self.on_data:

gui/tabs/terminal_tab.py

@@ -30,6 +30,10 @@ class TerminalTab(ctk.CTkFrame):
         self._terminal.pack(fill="both", expand=True, padx=5, pady=5)
         self._terminal.set_status(t("term_disconnected"), "#888888")
 
+        # Data batching buffer
+        self._data_buffer = bytearray()
+        self._flush_after_id = None
+
     def set_server(self, alias: str | None):
         if alias == self._current_alias:
             return
@@ -84,7 +88,16 @@ class TerminalTab(ctk.CTkFrame):
             self._session = None
 
     def _on_data_received(self, data: bytes):
-        self.after(0, lambda d=data: self._terminal.feed(d))
+        self._data_buffer.extend(data)
+        if self._flush_after_id is None:
+            self._flush_after_id = self.after(8, self._flush_data_buffer)
+
+    def _flush_data_buffer(self):
+        self._flush_after_id = None
+        if self._data_buffer:
+            chunk = bytes(self._data_buffer)
+            self._data_buffer.clear()
+            self._terminal.feed(chunk)
 
     def _on_disconnected(self):
         if self._intentional_disconnect:

gui/widgets/terminal_widget.py

@@ -73,12 +73,15 @@ class TerminalWidget(tk.Frame):
 
         # pyte screen + stream
         self._screen = pyte.Screen(cols, rows)
-        self._screen.set_mode(pyte.modes.LNM)
         self._stream = pyte.Stream(self._screen)
 
         # Previous buffer for diff rendering
         self._prev_buffer: dict[int, list] = {}
 
+        # Render debouncing (~60fps)
+        self._render_pending = False
+        self._render_after_id = None
+
         # Font
         self._font = tkfont.Font(family="Consolas", size=11)
         self._bold_font = tkfont.Font(family="Consolas", size=11, weight="bold")
@@ -147,12 +150,20 @@ class TerminalWidget(tk.Frame):
         self._status_label.configure(text=text, fg=color)
 
     def feed(self, data: bytes):
-        """Feed raw bytes from SSH into pyte and re-render."""
+        """Feed raw bytes from SSH into pyte, schedule debounced render."""
         try:
             text = data.decode("utf-8", errors="replace")
         except Exception:
             text = data.decode("latin-1", errors="replace")
         self._stream.feed(text)
+        if not self._render_pending:
+            self._render_pending = True
+            self._render_after_id = self.after(16, self._debounced_render)
+
+    def _debounced_render(self):
+        """Execute pending render."""
+        self._render_pending = False
+        self._render_after_id = None
         self._render()
 
     def reset(self):