Pane(fix[capture_pane]): -M captures mode screen, not escape markup

why: capture-pane -M captures from the mode screen (e.g. copy mode),
not escape markup. Verified in cmd-capture-pane.c:132 and tmux
CHANGES: "Add -M flag to capture-pane to use the copy mode screen."
what:
- Rename escape_markup param to mode_screen
- Update docstring and warning message
- Update test name and parameter usage

Author: tony

src/libtmux/pane.py

@@ -328,7 +328,7 @@ def capture_pane(
         trim_trailing: bool = False,
         alternate_screen: bool = False,
         quiet: bool = False,
-        escape_markup: bool = False,
+        mode_screen: bool = False,
     ) -> list[str]:
         r"""Capture text from pane.
 
@@ -384,8 +384,9 @@ def capture_pane(
             Default: False
 
             .. versionadded:: 0.45
-        escape_markup : bool, optional
-            Escape markup in the output (``-M`` flag). Requires tmux 3.6+.
+        mode_screen : bool, optional
+            Capture from the mode screen (e.g. copy mode) instead of the
+            pane (``-M`` flag). Requires tmux 3.6+.
             Default: False
 
             .. versionadded:: 0.45
@@ -440,12 +441,12 @@ def capture_pane(
             cmd.append("-a")
         if quiet:
             cmd.append("-q")
-        if escape_markup:
+        if mode_screen:
             if has_gte_version("3.6", tmux_bin=self.server.tmux_bin):
                 cmd.append("-M")
             else:
                 warnings.warn(
-                    "escape_markup requires tmux 3.6+, ignoring",
+                    "mode_screen requires tmux 3.6+, ignoring",
                     stacklevel=2,
                 )
         return self.cmd(*cmd).stdout

tests/test_pane_capture_pane.py

@@ -492,8 +492,8 @@ def test_capture_pane_alternate_screen(session: Session) -> None:
     assert isinstance(result, list)
 
 
-def test_capture_pane_escape_markup(session: Session) -> None:
-    """Test capture_pane with escape_markup flag (3.6+)."""
+def test_capture_pane_mode_screen(session: Session) -> None:
+    """Test capture_pane with mode_screen flag (3.6+)."""
     from libtmux.common import has_gte_version
 
     if not has_gte_version("3.6"):
@@ -502,5 +502,5 @@ def test_capture_pane_escape_markup(session: Session) -> None:
     pane = session.active_window.active_pane
     assert pane is not None
 
-    result = pane.capture_pane(escape_markup=True)
+    result = pane.capture_pane(mode_screen=True)
     assert isinstance(result, list)