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>

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):